The document discusses various joining processes including welding, brazing and soldering. It explains that brazing and soldering involve melting of a filler metal with brazing using higher temperatures and stronger fillers, while soldering uses lower temperatures and weaker tin-lead fillers. Welding involves melting the base metals. The document then goes on to describe various welding techniques like stick welding, MIG welding, TIG welding and spot welding. It also discusses factors like distortion and flaws in welds. The document also provides details about brazing and different types of solders, fluxes used and joint designs for soldering.
direct filling gold... material aspect, types, condensation, cavity design, modifications. detaied seminar for post gradutes.... any doubts or suggestions contact dr.mb@hotmail.com
The Indian Dental Academy is the Leader in continuing dental education , training dentists in all aspects of dentistry and
offering a wide range of dental certified courses in different formats.for more details please visit
www.indiandentalacademy.com
direct filling gold... material aspect, types, condensation, cavity design, modifications. detaied seminar for post gradutes.... any doubts or suggestions contact dr.mb@hotmail.com
The Indian Dental Academy is the Leader in continuing dental education , training dentists in all aspects of dentistry and
offering a wide range of dental certified courses in different formats.for more details please visit
www.indiandentalacademy.com
This presentation specifically deals with the maxillary and mandibular Major connectors used in a cast partial denture. it also mentions the uses, advantages and disadvantages of each,
In this lecture I explain in step-by-step fashion the basics of Endodontic Diagnosis: Pulp Vitality Tests. a photo guide is attached to the guide to aid in better understanding of the topic
Success of any dental procedure is determined by a good isolation. Here is a seminar on how to isolate the oral cavity from fluids and maintain a good dry field while working on a patient
The Indian Dental Academy is the Leader in continuing dental education , training dentists in all aspects of dentistry and
offering a wide range of dental certified courses in different formats.for more details please visit
www.indiandentalacademy.com
This presentation specifically deals with the maxillary and mandibular Major connectors used in a cast partial denture. it also mentions the uses, advantages and disadvantages of each,
In this lecture I explain in step-by-step fashion the basics of Endodontic Diagnosis: Pulp Vitality Tests. a photo guide is attached to the guide to aid in better understanding of the topic
Success of any dental procedure is determined by a good isolation. Here is a seminar on how to isolate the oral cavity from fluids and maintain a good dry field while working on a patient
The Indian Dental Academy is the Leader in continuing dental education , training dentists in all aspects of dentistry and
offering a wide range of dental certified courses in different formats.for more details please visit
www.indiandentalacademy.com
Soldering procedures /certified fixed orthodontic courses by Indian dental ac...Indian dental academy
The Indian Dental Academy is the Leader in continuing dental education , training dentists in all aspects of dentistry and offering a wide range of dental certified courses in different formats.
Indian dental academy provides dental crown & Bridge,rotary endodontics,fixed orthodontics,
Dental implants courses.for details pls visit www.indiandentalacademy.com ,or call
0091-9248678078
Metal Joining Processes: Welding, Riveting, Bolting, Brazing, SolderingJJ Technical Solutions
The presentation is a mechanical engineering presentation on the basics of metal joining processes. The basics of metal joining processes such as welding, riveting is explained in detail.
Understanding the welding process and troubleshooting.sourbhk6
This Tutorial will help newbee to understand the welding process and its trouble which are easy to sort out during the production. Just follow the tutorial and boost your knowledge to understand the welding process.
Flux: A Language for Programming High-Performance ServersEmery Berger
Flux is a concise programming language for writing servers that scale and are deadlock-free. A Flux programmer uses off-the-shelf, sequential C and C++ code, and describes their composition; the Flux compiler then generates a deadlock-free, high-concurrency server. Flux also makes it easy to analyze and predict server performance, because the Flux compiler can also generate discrete event simulators that reflect actual server performance.
Indian Dental Academy: will be one of the most relevant and exciting training
center with best faculty and flexible training programs for dental
professionals who wish to advance in their dental practice,Offers certified
courses in Dental implants,Orthodontics,Endodontics,Cosmetic Dentistry,
Prosthetic Dentistry, Periodontics and General Dentistry.
Finite Element Simulation Analysis of Double Nosing Process in the Assembly o...IJRES Journal
For spherical bearings, the osculation between inner and outer ring may be too big, too small or uneven after extrusion assembly. Based on the finite element software ABAQUS, according to the actual assembly situation of GE40 series of spherical plain bearings, the two-dimensional axisymmetric elasto-plastic finite element mode is built.. During the research of bearings extrusion deformation process, flow law of metal plastic forming will be concluded, meanwhile the contact stress distribution between the inner and the outer rings. During the research of bearings springback process, osculation will be obtained.
Computer Science
Active and Programmable Networks
Active safety systems
Ad Hoc & Sensor Network
Ad hoc networks for pervasive communications
Adaptive, autonomic and context-aware computing
Advance Computing technology and their application
Advanced Computing Architectures and New Programming Models
Advanced control and measurement
Aeronautical Engineering,
Agent-based middleware
Alert applications
Automotive, marine and aero-space control and all other control applications
Autonomic and self-managing middleware
Autonomous vehicle
Biochemistry
Bioinformatics
BioTechnology(Chemistry, Mathematics, Statistics, Geology)
Broadband and intelligent networks
Broadband wireless technologies
CAD/CAM/CAT/CIM
Call admission and flow/congestion control
Capacity planning and dimensioning
Changing Access to Patient Information
Channel capacity modelling and analysis
Civil Engineering,
Cloud Computing and Applications
Collaborative applications
Communication application
Communication architectures for pervasive computing
Communication systems
Computational intelligence
Computer and microprocessor-based control
Computer Architecture and Embedded Systems
Computer Business
Computer Sciences and Applications
Computer Vision
Computer-based information systems in health care
Computing Ethics
Computing Practices & Applications
Congestion and/or Flow Control
Content Distribution
Context-awareness and middleware
Creativity in Internet management and retailing
Cross-layer design and Physical layer based issue
Cryptography
Data Base Management
Data fusion
Data Mining
Data retrieval
Data Storage Management
Decision analysis methods
Decision making
Digital Economy and Digital Divide
Digital signal processing theory
Distributed Sensor Networks
Drives automation
Drug Design,
Drug Development
DSP implementation
E-Business
E-Commerce
E-Government
Electronic transceiver device for Retail Marketing Industries
Electronics Engineering,
Embeded Computer System
Emerging advances in business and its applications
Emerging signal processing areas
Enabling technologies for pervasive systems
Energy-efficient and green pervasive computing
Environmental Engineering,
Estimation and identification techniques
Evaluation techniques for middleware solutions
Event-based, publish/subscribe, and message-oriented middleware
Evolutionary computing and intelligent systems
Expert approaches
Facilities planning and management
Flexible manufacturing systems
Formal methods and tools for designing
Fuzzy algorithms
Fuzzy logics
GPS and location-based app
Connectors –in fpd /certified fixed orthodontic courses by Indian dental acad...Indian dental academy
The Indian Dental Academy is the Leader in continuing dental education , training dentists in all aspects of dentistry and offering a wide range of dental certified courses in different formats.
Indian dental academy provides dental crown & Bridge,rotary endodontics,fixed orthodontics,
Dental implants courses.for details pls visit www.indiandentalacademy.com ,or call
0091-9248678078
the making of articles on a large scale using machinery; industrial production. "even in manufacturing they no longer dominate"Manufacturing is the process of turning raw materials or parts into finished goods through the use of tools, human labor, machinery, and chemical processing. Most products were handmade using human labor and basic tools before the Industrial Revolution.
What are the 4 types of manufacturing process?
Casting and molding.
Machining.
Joining.
Shearing and forming.
Stainless steel is one of the most widely used materials in dentistry for the production of dental instruments, e.g. scalpel blades and forceps, orthodontic wires, denture bases and partial denture clasps, endodontic posts and as stainless steel crowns for the treatment of severely decayed primary molars.
Soldering and Brazing are an integral part of dentistry, especially in prosthodontics and crown and bridge procedure. it is also used in implant-supported prosthetics.
New Directions in Targeted Therapeutic Approaches for Older Adults With Mantl...i3 Health
i3 Health is pleased to make the speaker slides from this activity available for use as a non-accredited self-study or teaching resource.
This slide deck presented by Dr. Kami Maddocks, Professor-Clinical in the Division of Hematology and
Associate Division Director for Ambulatory Operations
The Ohio State University Comprehensive Cancer Center, will provide insight into new directions in targeted therapeutic approaches for older adults with mantle cell lymphoma.
STATEMENT OF NEED
Mantle cell lymphoma (MCL) is a rare, aggressive B-cell non-Hodgkin lymphoma (NHL) accounting for 5% to 7% of all lymphomas. Its prognosis ranges from indolent disease that does not require treatment for years to very aggressive disease, which is associated with poor survival (Silkenstedt et al, 2021). Typically, MCL is diagnosed at advanced stage and in older patients who cannot tolerate intensive therapy (NCCN, 2022). Although recent advances have slightly increased remission rates, recurrence and relapse remain very common, leading to a median overall survival between 3 and 6 years (LLS, 2021). Though there are several effective options, progress is still needed towards establishing an accepted frontline approach for MCL (Castellino et al, 2022). Treatment selection and management of MCL are complicated by the heterogeneity of prognosis, advanced age and comorbidities of patients, and lack of an established standard approach for treatment, making it vital that clinicians be familiar with the latest research and advances in this area. In this activity chaired by Michael Wang, MD, Professor in the Department of Lymphoma & Myeloma at MD Anderson Cancer Center, expert faculty will discuss prognostic factors informing treatment, the promising results of recent trials in new therapeutic approaches, and the implications of treatment resistance in therapeutic selection for MCL.
Target Audience
Hematology/oncology fellows, attending faculty, and other health care professionals involved in the treatment of patients with mantle cell lymphoma (MCL).
Learning Objectives
1.) Identify clinical and biological prognostic factors that can guide treatment decision making for older adults with MCL
2.) Evaluate emerging data on targeted therapeutic approaches for treatment-naive and relapsed/refractory MCL and their applicability to older adults
3.) Assess mechanisms of resistance to targeted therapies for MCL and their implications for treatment selection
Flu Vaccine Alert in Bangalore Karnatakaaddon Scans
As flu season approaches, health officials in Bangalore, Karnataka, are urging residents to get their flu vaccinations. The seasonal flu, while common, can lead to severe health complications, particularly for vulnerable populations such as young children, the elderly, and those with underlying health conditions.
Dr. Vidisha Kumari, a leading epidemiologist in Bangalore, emphasizes the importance of getting vaccinated. "The flu vaccine is our best defense against the influenza virus. It not only protects individuals but also helps prevent the spread of the virus in our communities," he says.
This year, the flu season is expected to coincide with a potential increase in other respiratory illnesses. The Karnataka Health Department has launched an awareness campaign highlighting the significance of flu vaccinations. They have set up multiple vaccination centers across Bangalore, making it convenient for residents to receive their shots.
To encourage widespread vaccination, the government is also collaborating with local schools, workplaces, and community centers to facilitate vaccination drives. Special attention is being given to ensuring that the vaccine is accessible to all, including marginalized communities who may have limited access to healthcare.
Residents are reminded that the flu vaccine is safe and effective. Common side effects are mild and may include soreness at the injection site, mild fever, or muscle aches. These side effects are generally short-lived and far less severe than the flu itself.
Healthcare providers are also stressing the importance of continuing COVID-19 precautions. Wearing masks, practicing good hand hygiene, and maintaining social distancing are still crucial, especially in crowded places.
Protect yourself and your loved ones by getting vaccinated. Together, we can help keep Bangalore healthy and safe this flu season. For more information on vaccination centers and schedules, residents can visit the Karnataka Health Department’s official website or follow their social media pages.
Stay informed, stay safe, and get your flu shot today!
NVBDCP.pptx Nation vector borne disease control programSapna Thakur
NVBDCP was launched in 2003-2004 . Vector-Borne Disease: Disease that results from an infection transmitted to humans and other animals by blood-feeding arthropods, such as mosquitoes, ticks, and fleas. Examples of vector-borne diseases include Dengue fever, West Nile Virus, Lyme disease, and malaria.
- Video recording of this lecture in English language: https://youtu.be/lK81BzxMqdo
- Video recording of this lecture in Arabic language: https://youtu.be/Ve4P0COk9OI
- Link to download the book free: https://nephrotube.blogspot.com/p/nephrotube-nephrology-books.html
- Link to NephroTube website: www.NephroTube.com
- Link to NephroTube social media accounts: https://nephrotube.blogspot.com/p/join-nephrotube-on-social-media.html
micro teaching on communication m.sc nursing.pdfAnurag Sharma
Microteaching is a unique model of practice teaching. It is a viable instrument for the. desired change in the teaching behavior or the behavior potential which, in specified types of real. classroom situations, tends to facilitate the achievement of specified types of objectives.
These lecture slides, by Dr Sidra Arshad, offer a quick overview of physiological basis of a normal electrocardiogram.
Learning objectives:
1. Define an electrocardiogram (ECG) and electrocardiography
2. Describe how dipoles generated by the heart produce the waveforms of the ECG
3. Describe the components of a normal electrocardiogram of a typical bipolar leads (limb II)
4. Differentiate between intervals and segments
5. Enlist some common indications for obtaining an ECG
Study Resources:
1. Chapter 11, Guyton and Hall Textbook of Medical Physiology, 14th edition
2. Chapter 9, Human Physiology - From Cells to Systems, Lauralee Sherwood, 9th edition
3. Chapter 29, Ganong’s Review of Medical Physiology, 26th edition
4. Electrocardiogram, StatPearls - https://www.ncbi.nlm.nih.gov/books/NBK549803/
5. ECG in Medical Practice by ABM Abdullah, 4th edition
6. ECG Basics, http://www.nataliescasebook.com/tag/e-c-g-basics
Explore natural remedies for syphilis treatment in Singapore. Discover alternative therapies, herbal remedies, and lifestyle changes that may complement conventional treatments. Learn about holistic approaches to managing syphilis symptoms and supporting overall health.
Knee anatomy and clinical tests 2024.pdfvimalpl1234
This includes all relevant anatomy and clinical tests compiled from standard textbooks, Campbell,netter etc..It is comprehensive and best suited for orthopaedicians and orthopaedic residents.
ARTIFICIAL INTELLIGENCE IN HEALTHCARE.pdfAnujkumaranit
Artificial intelligence (AI) refers to the simulation of human intelligence processes by machines, especially computer systems. It encompasses tasks such as learning, reasoning, problem-solving, perception, and language understanding. AI technologies are revolutionizing various fields, from healthcare to finance, by enabling machines to perform tasks that typically require human intelligence.
Ozempic: Preoperative Management of Patients on GLP-1 Receptor Agonists Saeid Safari
Preoperative Management of Patients on GLP-1 Receptor Agonists like Ozempic and Semiglutide
ASA GUIDELINE
NYSORA Guideline
2 Case Reports of Gastric Ultrasound
Ethanol (CH3CH2OH), or beverage alcohol, is a two-carbon alcohol
that is rapidly distributed in the body and brain. Ethanol alters many
neurochemical systems and has rewarding and addictive properties. It
is the oldest recreational drug and likely contributes to more morbidity,
mortality, and public health costs than all illicit drugs combined. The
5th edition of the Diagnostic and Statistical Manual of Mental Disorders
(DSM-5) integrates alcohol abuse and alcohol dependence into a single
disorder called alcohol use disorder (AUD), with mild, moderate,
and severe subclassifications (American Psychiatric Association, 2013).
In the DSM-5, all types of substance abuse and dependence have been
combined into a single substance use disorder (SUD) on a continuum
from mild to severe. A diagnosis of AUD requires that at least two of
the 11 DSM-5 behaviors be present within a 12-month period (mild
AUD: 2–3 criteria; moderate AUD: 4–5 criteria; severe AUD: 6–11 criteria).
The four main behavioral effects of AUD are impaired control over
drinking, negative social consequences, risky use, and altered physiological
effects (tolerance, withdrawal). This chapter presents an overview
of the prevalence and harmful consequences of AUD in the U.S.,
the systemic nature of the disease, neurocircuitry and stages of AUD,
comorbidities, fetal alcohol spectrum disorders, genetic risk factors, and
pharmacotherapies for AUD.
Title: Sense of Smell
Presenter: Dr. Faiza, Assistant Professor of Physiology
Qualifications:
MBBS (Best Graduate, AIMC Lahore)
FCPS Physiology
ICMT, CHPE, DHPE (STMU)
MPH (GC University, Faisalabad)
MBA (Virtual University of Pakistan)
Learning Objectives:
Describe the primary categories of smells and the concept of odor blindness.
Explain the structure and location of the olfactory membrane and mucosa, including the types and roles of cells involved in olfaction.
Describe the pathway and mechanisms of olfactory signal transmission from the olfactory receptors to the brain.
Illustrate the biochemical cascade triggered by odorant binding to olfactory receptors, including the role of G-proteins and second messengers in generating an action potential.
Identify different types of olfactory disorders such as anosmia, hyposmia, hyperosmia, and dysosmia, including their potential causes.
Key Topics:
Olfactory Genes:
3% of the human genome accounts for olfactory genes.
400 genes for odorant receptors.
Olfactory Membrane:
Located in the superior part of the nasal cavity.
Medially: Folds downward along the superior septum.
Laterally: Folds over the superior turbinate and upper surface of the middle turbinate.
Total surface area: 5-10 square centimeters.
Olfactory Mucosa:
Olfactory Cells: Bipolar nerve cells derived from the CNS (100 million), with 4-25 olfactory cilia per cell.
Sustentacular Cells: Produce mucus and maintain ionic and molecular environment.
Basal Cells: Replace worn-out olfactory cells with an average lifespan of 1-2 months.
Bowman’s Gland: Secretes mucus.
Stimulation of Olfactory Cells:
Odorant dissolves in mucus and attaches to receptors on olfactory cilia.
Involves a cascade effect through G-proteins and second messengers, leading to depolarization and action potential generation in the olfactory nerve.
Quality of a Good Odorant:
Small (3-20 Carbon atoms), volatile, water-soluble, and lipid-soluble.
Facilitated by odorant-binding proteins in mucus.
Membrane Potential and Action Potential:
Resting membrane potential: -55mV.
Action potential frequency in the olfactory nerve increases with odorant strength.
Adaptation Towards the Sense of Smell:
Rapid adaptation within the first second, with further slow adaptation.
Psychological adaptation greater than receptor adaptation, involving feedback inhibition from the central nervous system.
Primary Sensations of Smell:
Camphoraceous, Musky, Floral, Pepperminty, Ethereal, Pungent, Putrid.
Odor Detection Threshold:
Examples: Hydrogen sulfide (0.0005 ppm), Methyl-mercaptan (0.002 ppm).
Some toxic substances are odorless at lethal concentrations.
Characteristics of Smell:
Odor blindness for single substances due to lack of appropriate receptor protein.
Behavioral and emotional influences of smell.
Transmission of Olfactory Signals:
From olfactory cells to glomeruli in the olfactory bulb, involving lateral inhibition.
Primitive, less old, and new olfactory systems with different path
New Drug Discovery and Development .....NEHA GUPTA
The "New Drug Discovery and Development" process involves the identification, design, testing, and manufacturing of novel pharmaceutical compounds with the aim of introducing new and improved treatments for various medical conditions. This comprehensive endeavor encompasses various stages, including target identification, preclinical studies, clinical trials, regulatory approval, and post-market surveillance. It involves multidisciplinary collaboration among scientists, researchers, clinicians, regulatory experts, and pharmaceutical companies to bring innovative therapies to market and address unmet medical needs.
2. Joining Processes: Welding, Brazing, Soldering
1. Brazing and Soldering: Melting of filler only
• Brazing: higher temperature, ~brass filler, strong
• Soldering: lower temp, ~tin-lead filler, weak
2. Welding: Melting of base metals
3. Both: Join parts to form complex product
sales.nordex-online.com
3. • Definition of welding proposed by the AWS is
an
• "operation which aims to get localized
coalescence produced by heating to a
suitable temperature, with or without
applying pressure and filler metal,
producing parts with strong welded
union, nonporous and free of corrosion.”
4. Brazing
• Steel base metal + Brass filler rod is
common
• Lower temp than welding: retains heat
treatment (if present), minimizes grain
growth.
• Strong but slow (careful preparation,
cleanup)
• Furnace brazing is easily automated
5. TYPES OF WELDING
• Stick Welding
• Metal Inert Gas Welding
• Tungsten Inert Gas Welding
• Spot Welding
6. Shielded Metal Arc Welding (SMAW): “Stick welding”
• Older, simple technology
• The electrode is also the filler rod
• Only for steel
• Strong welds if done properly (but often not)
• Very high heat input: good for thick parts, bad for grain
growth and distortion
7. Gas Metal Arc Welding (GMAW): “MIG” (Metal-Inert-Gas)
• ~Complex mechanism but simple to perform and easy to automate
• The electrode is also the filler rod, fed continuously from a spool. It
melts in the arc.
• For steel or aluminum
• Low skill level can achieve good weld
• Medium heat input: distortion and grain growth are significant
9. Gas Tungsten Arc Welding (GTAW): “TIG” (Tungsten-Inert-Gas)
• The electrode is tungsten (not consumed)
• The filler rod is separate and fed manually
• High skill level required to achieve good weld
• Difficult to automate
• Low heat input and small weld bead: distortion and grain growth are
minimized
10. Gas Tungsten Arc Welding (GTAW): “TIG” (Tungsten-Inert-Gas)
• Typical good quality TIG welds
11. Resistance Spot Welding (RSW): “Spot Welding”
• No filler rod: electrical current is passed through metal under
pressure
• Low skill level required
• Easy to automate
• Low heat input and no weld bead: distortion and grain growth are
minimized
12. Distortion from Welding Processes
• Non-uniform shrinkage of weld bead
• Difficult to maintain alignments
• Solution: Rigid fixtures, pre-compensate for warping, loose
tolerances
13. Weld bead profile: Convex or Concave?
• Solidification of molten bead leads to shrinkage
• Shrinkage of a concave bead leads to tension on surface
tends to crack
• Shrinkage of a convex bead leads to compression on surface
does not crack
• Generally, slightly convex beads are preferred.
17. DEFINITION
• Soldering involves joining two
components of metal with an
intermediate metal whose melting
temperature is lower than the parent
metal.
It’s defined as the joining of
metals by the fusion of filler
metal between them, at a
temperature below the
solidus temperature of the
metals being joined and
below 450°C.
18. Silver solders
•They are low fusing –fusion temp-600-750°C
•Used with stainless steel or other base metal
alloys
•Resistance to tarnish and corrosion is not as
good as gold solders
•But have strength comparable to gold solders
•Composition
•Silver -10-80 %
•Copper -15-30%
•Zinc -4-35%
•with small amounts of cadmium, tin and
phosphorus.
•The formation of silver-copper eutectic is
responsible for the low melting range of silver
solder.
19. • HEAT SOURCE
• The most common instrument used as heat source
is gas- air or gas- oxygen torch. The type of torch
depends on the type of fuel.
• The fuels used are :-
• Hydrogen -low heat content, so heating is slow.
• Natural gas - heat content is four times that of
hydrogen.
• Acetylene - high flame temperature, but variation in
temperature from one part of the flame to the other
part is more than 100°C. So positioning of the torch
is critical. It is chemically unstable gas, decompose
to carbon and hydrogen. carbon can get
incorporated in to nickel and palladium alloys.
• Propane - is the best choice. Have highest heat
content & good flame temperature.
• Butane - has similar flame temperature and heat
content. Both are readily available. Uniform in
quality, virtually water free and burn clean.
20. • FLAME The flame can be divided in to four zones
• Cold mixing zone (unburned gas)
• Partial combustion zone (neutral zone)
• Reducing zone
• Oxidizing zone (burned gas).
• The portion of the flame that is used to heat the
soldering assembly should be the neutral or slightly
reducing part, because this produces the most
efficient burning process and most heat.
• Improperly adjusted torch or improperly positioned
flame can lead to oxidation of the substrate or filler
metal and result in a poorly soldered joint.
• If unburned portion of flame is used carbon may be
introduced to the substrate or filler.
• To prevent oxide formation the flame should not be
removed once it has been applied to the joint area
until soldering process has been completed.
21. PARENT METAL
•The parent metal is the metal or alloy to be joined. This
is also known as a substrate metal or base metal.
Soldering operation is the same for any substrate metal,
but the ease of soldering is not same for any substrate
metal.
The composition of parent metal determines-
•Melting range
•Oxide that forms on the surface during heating
• Wettability of the substrate by the molten solder.
• Soldering should take place below the solidus
temperature of the parent metal.
22. • Composition of alloy determines
• the oxides that form on its surface during
heating. The flux used should be able to reduce
these oxides, inhibit further oxidation and
facilitate its removal.
• the wettability of the substrate by the molten
solder alloy. The solder chosen must wet the
metal at as low a contact angle as possible to
ensure wetting of the joint area.
• Manufacturer of the alloy should provide
guidance and instruction regarding the flux to be
used with that alloy.
• A low temp soldering is preferred rather than
the high temp soldering for Stainless steel wire
to prevent carbide precipitation and to prevent
an excessive softening of the wire. So silver
solders are generally preferred.
23. REQUIREMENTS OF A SOLDER
• Fuse safely below the sag or creep temperature
of the parent alloy.
• Resist tarnish and corrosion.
• Non pitting.
• Free flowing.
• Match the color of the parent metal.
24. JOINT DESIGN
• Spacing between parts being joined greatly
affects tensile strength
• Strongest joints are obtained when parts use lap
or scarf joints
• Some joints can be designed so that the flux
and filler metal may be preplaced
• Joint preparation is very important
26. • CLASSIFICATION OF SOLDERS
• Soft solders
• Hard solders
• Precious metal solders
• Non precious metal solders
• SOFT SOLDERS They are lead- tin eutectic alloy
with a low melting point. Sometimes called as
plumbers solder. They have low fusion range of
about 260°C or less. Soft solders lack corrosion
resistance, so they are impractical for dental use.
• HARD SOLDERS Hard solders have higher meting
temperature & possess greater hardness and
strength. Heating is done with gas torch or special
devices. Two types of hard solders are used in
dentistry
27. COMPOSITION OF SOLDERS
• Gold
• Silver
• Copper
• Tin
• Zinc
• Gold solders are designated by fineness.
28. SOLDERING FLUX
• Flux means flow.
• Improve the flow of a metal
• Chemicals that limit the flow of metals
are called antifluxes
29. FUNCTIONS AND TYPES OF A FLUX
• PROTECTOR
It covers the metal surface and prevents oxide formation.
• REDUCER
It helps to reduce the oxides present on the metal
surface.
• SOLVENTS
It dissolves any oxide presence and removes it.
The resulting solution of oxides or other extraneous matter in
flux constitutes “slag”.
30. COMPOSITION OF A FLUX
• Borax glass
• Boric acid
• Silica
• Fluoride
According to their composition
Borax fluxes
Fluoride fluxes
According to the pH of the flux
•Acidic fluxes – SiO2
•Basic fluxes – CaO, lime CaCO3
LIMESTONE
•Neutral – Fluorspar
(Ca.F2),Borax (Na2B4O2)
31. • BORAX FLUXES
• Borax from Persian burah
• Also called sodium borate , or sodium tetraborate , or
disodium Tetraborate. They are based on boric or borate
compounds such as boric acid/boric anhydrate and
borax.
• It is usually a white powder consisting of soft colourless
crystals that dissolve easily in water.
• Borax has a wide variety of uses:-
• It is a component of many detergents, cosmetics, and
enamel glazes.
• It is also used to make buffer solutions in biochemistry
as a fire retardant as an insecticide as a flux in
metallurgy.
• They act as protective fluxes and reducing fluxes for low
stability. oxides such as copper oxide and are used for
noble metal alloys.
32. • They are available in
• Liquid form : Solution of borax/boric acid in
water. Indicated for soldering of orthodontic
appliances and bridges in which minimum
amount of flux is required.
• Paste form : Formed by mixing borax with
petroleum jelly. Required when fluxes are
needed in large quantity.
• Powder form : Contains a mixture of borax,
basic acid, silica flour and finely divided
charcoal. Charcoals reducing agent and silica
holds molten flux in surface of hot metal. This
is usually used for casting operation.
33. • FLUORIDE FLUXES
• Composition:-
• Potassium fluoride – 50-60%
• Borax glass - 6-8%
• Potassium carbonate – 8-10%
• As the choice of flux is dictated by the type of
alloys to be soldered, the fluoride flux is used
with alloys containing base metals even if a
gold/silver solder is used. Some fluoride
containing fluxes involve toxic fluorides when
heated, so inhalation of fumes should be
avoided.
34. SUPER FLUX
•A combination of high melting salts is used
as fluxes to combine the good characteristics
of each ingredient and create superior flux.
•A formula for efficient flux is
• Borax glass – 55 parts
•Boric acid – 35 parts
•Silica - 10 parts
•The ingredients may be fused together and
then crushed to fine powder.
35. • Too little flux tends to burn off and will be
ineffective.
• Excess flux remains trapped within filler metal
and cause a weakened joint.
• Flux combined with metal oxides forms a glass
during soldering process that is difficult to
remove completely. A two step method for
removing residual flux
• Blast joint immediately after removal from
investment with alumina abrasive particles
followed by boiling in water for about 5
minutes.
36. ANTIFLUX
• Used to restrict the flow of the metal.
• Most common anti-fluxes used is graphite.
• Better fluxes like Rouge in chloroform can
be used.
• It is applied on the surface of specific area
where the solder should not flow into. It is
applied before applying flux or solder.
• E.g.: Graphite in the form of lead pencil.
Disadvantage of graphite is that it can burn
off on prolonged heating at high
temperature.
• In such cases whiting (CaCO3 in alcohol and
water suspension) is used.
37. QUALITIES OF AN IDEAL SOLDER
• FILLER METAL/SOLDER
• Ease of flow at relatively low temperature.
• Sufficient fluidity to freely flow when melted.
• Ability to wet substrate metal.
• Strength compatible with that of the structure
being joined. Resistance to tarnish and
corrosion.
• Acceptable colour to give an inconspicuous
joint.
• Resistance to pitting during heating.
38. The joining area should be three times the thickness of the
thinnest joint member.
39. When building up a surface, alternate the direction of each layer
40. Best types of flame to use:
•Air acetylene
•Air MAPP
•Air propane
•Any air fuel-gas mixture
42. TORCH SOLDERING
• Soldering is done under direct flame.
• A gas air torch is used for this purpose.
• The torch flame has two parts – the
reducing part (is at a higher temperature)
and the soft brush part.
43. • The solder should be melted using the
soft brush flame.
• The flame should be constantly swiped
over the solder for a period of 4 -5
minutes.
• At no point of time the flame should be
held in a stationary position.
44. INFRARED SOLDERING
• Used for low fusing connectors.
• Good accuracy.
• Similar strength as conventional
soldering.
• Protective eyewear is necessary.
45. LASER SOLDERING
• Done to join Ti components of dental
crowns, bridges and partial denture
frame works.
• Pulsed high power Neodymium lasers are
used.
• Low thermal influence preferred in
dentistry.
• Superior joint strength.
46. FURNACE SOLDERING
• Advantages of using a furnace:
• Furnace brazing is a semi-automatic process
• Temperature control
• Controlled atmosphere (Common atmospheres
used include: inert, reducing or vacuum
atmospheres all of which protect the part from
oxidation)
• Uniform heating
• Mass production
• Disadvantages of using a furnace:
• Size
• Heat damage
48. SOLDERING TECHNIQUE
• The design of the connector is
determined while fabricating the wax
pattern.
• All the solder connectors require about
0.25mm parallel spaced between the
parent components.
• The smaller units are inserted separately
in the mouth.
49. • A thick mix of quick setting plaster is molded
over the inserted units.
• Once the plaster sets, it is removed along with
the inserted units.
• Plaster index is inverted.
• Components of the prosthesis will be visible.
50. • A triangular piece of utility wax should
be placed to index restoration in order to
shape the soldering assembly.
• The units are invested and the
investment is allowed to bench set.
• Invested wax is eliminated using boiling
water or chloroform.
51. • Area of the restoration surrounding the
joint should be coated with anti-flux.
• After coating the flux and the anti-flux,
the assembly is preheated in a burnout
furnace.
• Connectors are soldered using a torch or
a furnace.
52. • The parts to be joined are fixtured and the brazing
compound applied to the mating surfaces, typically in
slurry form. Then the assemblies are dipped into a bath
of molten salt (typically NaCl, KCl and other compounds)
which functions both as heat transfer medium and flux.
• Advantages of dip processing:
• Mass production
• Corrosion protection
• Distortion minimized
• Disadvantages of dip processing:
• Steam explosions
• Corrosion
• Size
• Quantity
53. CERAMIC/ACRYLIC VENEERING
• The ceramic or acrylic veneers in metal resin
or metal ceramic restorations are usually
added after soldering.
• Ceramic veneering is done in 3 steps
1. METAL PREPARATION.
2. PORCELAIN APPLICATION.
3. PORCELAIN FIRING.
54. SOLDERING INVESTMENT
• These are silica –bonded investments
that are fused quartz.
• Fused quartz is used because it is the
lowest thermally expanding form of
silica.
55. SOLDERING FOR METAL CERAMIC
RESTORATION
• It is usually done prior to ceramic application
hence it is also known as pre ceramic
soldering.
• Post ceramic materials are also available.
56. • Pre ceramic soldering is done at a temperature
of 1075 to 1120 degree celsius whereas post
ceramic soldering should be done at a
temperature of 920 degree celsius because
ceramic may begin to sag at higher
temperatures.
57. SOLDERING INVESTMENT
• These are silica –bonded investments
that are fused quartz.
• Fused quartz is used because it is the
lowest thermally expanding form of
silica.
58. SOLDERING FOR METAL CERAMIC
RESTORATION
• It is usually done prior to ceramic application
hence it is also known as pre ceramic
soldering.
• Post ceramic materials are also available.
59. • Post ceramic soldering should be done
after ceramic firing.
• Ceramic portions should be finished only
after soldering.
60. ADVANTAGES OF PRE CERAMIC
SOLDERING
• The metal framework can be soldered
and tried in prior to ceramic build up.
• Minor casting errors can also be patched
up during ceramic build up.
61. DISADVANTAGES OF PRE CERAMIC
SOLDERING
• Difficult to build ceramic on already
soldered units.
62. ADVANTAGES OF POST CERAMIC
SOLDERING
• Porcelain can be properly build up due to
better access.
63. DISADVANTAGES OF POST CERAMIC
SOLDERING
• The metal and porcelain may sag at high
soldering temperatures.
• It is more technique sensitive.
• The solder should be re-glazed and re-
fired.
64. OVEN SOLDERING
• Performed under vacuum or air.Performed under vacuum or air.
• A piece of solder is placed in the jointA piece of solder is placed in the joint
space and it is heated to a standardspace and it is heated to a standard
temperature in the furnace.temperature in the furnace.
• Superior joint strength.Superior joint strength.
65. DISADVANTAGES
• The parent metal will sag or melt ifThe parent metal will sag or melt if
heated for a long time.heated for a long time.
66. SOLDERING FAILURES
• Failure to clean the parts to be joined
• Improper fluxing
• Poor flow of solder
• Over heating of the solder can lead to pitted joint of low
strength Besides porosities and brittleness from oxides,
gases, or foreign matter resulting from the soldering
procedures as factors for increasing the incidences of failure
of soldered joints.
• Creep, corrosion, stress corrosion cracking, corrosion-fatigue,
and corrosion-erosion.
• Gas embitterment can also be generated by gases formed
from electrochemical processes. Hydrogen embitterment
from corrosion is a very well-known phenomenon that occurs
with some material-solution combinations and at
temperatures comparable to physiologic conditions.
67. CONCLUSION
• The choice of solder material has extreme importance in
determining the properties of the soldered joints. Silver solders
are popular because of their lower fusion temperatures and
easy-handling characteristics. Soldering is still a useful and
needed procedure for the joining of metallic parts. The choice of
whether free-hand or investment, torch or oven, or pre or post
ceramic soldering techniques are used, as well as variations in
gap distance and high- or low-fusing soldering alloys, is in many
instances up to the discretion of the dental surgeon and
technician. The breakage of soldered components is one of the
pitfalls associated with this joining procedure. Even though
following guidelines should theoretically prevent them from
occurring, solder failures are not rare.