This document discusses various types of wear mechanisms that can occur in machines. It defines 11 main types of wear: adhesive, abrasive, erosion, polishing, contact fatigue, corrosive, electro-corrosive, fretting, electrical discharge, cavitation, and false brinelling wear. For each type of wear, it describes the wear process and provides recommendations for both mechanical and lubricant-based prevention methods. Microscopic analysis of wear debris is also discussed as a way to determine the specific type of wear that occurred.
Wear is a process of removal of material from one or both of two solid surfaces in solid state contact, occurring when these two solid surfaces are in sliding or rolling motivation
Electron Beam Welding is a fusion welding process in which a beam of high-velocity electrons is applied to the material to be joined. The work-piece melt as the kinetic energy of the electrons is transformed into heat upon impact. The EBW process is well-positioned to provide industries with highest quality welds and machine designs that have proven to be adaptable to specific welding tasks and production environments.
NON DESTRUCTIVE TESTING TECHNIQUES ARE USEFUL FOR FINDING DEFECTS LIKE CRACKS,POROSITY,FLAWS,BLOWHOLES IN MATERIALS WITHOUT DESTRUCTING COMPONENT. IT IS ALSO USEFUL FOR TAKING DECISIONS RELATED TO QUALITY OF MATERIAL OR PRODUCT. Non destructive testing includes study and testing of components by various methods such as dye penetration test, eddy current test, magnetic particle test, ndt, radiography test, ultrasonic test.
Wear is a process of removal of material from one or both of two solid surfaces in solid state contact, occurring when these two solid surfaces are in sliding or rolling motivation
Electron Beam Welding is a fusion welding process in which a beam of high-velocity electrons is applied to the material to be joined. The work-piece melt as the kinetic energy of the electrons is transformed into heat upon impact. The EBW process is well-positioned to provide industries with highest quality welds and machine designs that have proven to be adaptable to specific welding tasks and production environments.
NON DESTRUCTIVE TESTING TECHNIQUES ARE USEFUL FOR FINDING DEFECTS LIKE CRACKS,POROSITY,FLAWS,BLOWHOLES IN MATERIALS WITHOUT DESTRUCTING COMPONENT. IT IS ALSO USEFUL FOR TAKING DECISIONS RELATED TO QUALITY OF MATERIAL OR PRODUCT. Non destructive testing includes study and testing of components by various methods such as dye penetration test, eddy current test, magnetic particle test, ndt, radiography test, ultrasonic test.
GMT started manufacturing lapping & polishing machine in 1971. It was built for in-house use and until then hand lapping process was used for finishing surface plates. Critical parts for our workholding devices required a finishing and buffing machine. There was demand in the market for valve lapping and lapping plates. Since GMT had a captive ferrous foundry, castings for lap plate and lapping machine were easier to source.
Since then GMT has become one of India's largest lapping machine manufacturers and suppliers with over 350 installations throughout India mainly to the valve and pump industry. When a buyer in Japan wanted a super finishing machine for lapping large granite plates, GMT designed and supplied a 3000mm dia flat lapping machine.
Pump manufacturers, electronic industries, valve manufacturers, etc., have found a sure way of obtaining positive sealing.
presentation is divided into three parts,
1)spur gears failure
2)Beam Strength while designing spur gears
3)Wear Strength while designing spur gears
this is not all for spur gears,just a part of design
In diesem Wintersemester halte ich an der Johannes-Kepler-Universität Linz einmal mehr die LVA 'Grundlagen Privatrecht' im Masterstudium Webwissenschaften ab. Es freut mich besonders, die LVA diesmal nicht alleine, sondern gemeinsam mit Mag. Ecker im Co-Teaching durchführen zu können.
Hier finden Sie die Folien meines Teils der LVA, konkret ab Kapitel 4 mit Schwerpunkt auf Webrecht. Mag. Ecker befasst sich seinerseits in seinem Teil mit den Grundlagen und dem Vertragsrecht.
GMT started manufacturing lapping & polishing machine in 1971. It was built for in-house use and until then hand lapping process was used for finishing surface plates. Critical parts for our workholding devices required a finishing and buffing machine. There was demand in the market for valve lapping and lapping plates. Since GMT had a captive ferrous foundry, castings for lap plate and lapping machine were easier to source.
Since then GMT has become one of India's largest lapping machine manufacturers and suppliers with over 350 installations throughout India mainly to the valve and pump industry. When a buyer in Japan wanted a super finishing machine for lapping large granite plates, GMT designed and supplied a 3000mm dia flat lapping machine.
Pump manufacturers, electronic industries, valve manufacturers, etc., have found a sure way of obtaining positive sealing.
presentation is divided into three parts,
1)spur gears failure
2)Beam Strength while designing spur gears
3)Wear Strength while designing spur gears
this is not all for spur gears,just a part of design
In diesem Wintersemester halte ich an der Johannes-Kepler-Universität Linz einmal mehr die LVA 'Grundlagen Privatrecht' im Masterstudium Webwissenschaften ab. Es freut mich besonders, die LVA diesmal nicht alleine, sondern gemeinsam mit Mag. Ecker im Co-Teaching durchführen zu können.
Hier finden Sie die Folien meines Teils der LVA, konkret ab Kapitel 4 mit Schwerpunkt auf Webrecht. Mag. Ecker befasst sich seinerseits in seinem Teil mit den Grundlagen und dem Vertragsrecht.
Industeel : the right steel at the right place
http://industeel.arcelormittal.com/
Special steel plate / Stainless / Cryogenic / Hot rolled steel plate / Heavy plate / Mould steel / Wear resistant steel / Pressure vessel / Engineering / Tools & dies / Austenitic / Ferritic / Martensitic / alloys / Protection steel
Special steel
Steel Plate
Heavy Plate
Techniques for preventing wear & abrasionVortex
Generally speaking, a manufacturing process will likely realize its highest degree of wear in areas where material flow pattern or air pressure are subjected to dramatic change or disruption. This includes elbows in system ductwork, directional changes from diverting or converging, sudden halt in material flow, aspiration of displaced air, and many other variables in system design.
Depending on application parameters, several techniques can be utilized to protect a system from rapid wear and abrasion.
Abrasive and impact-abrasive wear testing of steels for mining, transporting,...Vilma Ratia
Presentation given at Hard rock tribology seminar 4-5.11.2014 at Tampere University of Technology, Finland
Information about the equiopment can be found at http://www.tut.fi/twc/en
Articles including measurement data can be found at https://www.researchgate.net/profile/Vilma_Ratia
The selling environment in which a firm produces and sells its product is called a market structure.*
Defined by three characteristics:
The number of firms in the market
The ease of entry and exit of firms
The degree of product differentiation
Araldite Preparacion superficial y pretatamientos. Antala Industria (Spain).Antala Industria
El éxito en las uniones depende de una combinación de múltiples factores, tales como mecánicos, químicos o electrostáticos. La unión es una cuestión de interfaz, ya que el adhesivo tiene que adherirse bien a los sustratos a unir. Por lo tanto, las condiciones de la superficie de las piezas a unir son un factor esencial en el logro de una unión de calidad.
Los Adhesivos industriales Huntsman son adhesivos de alto rendimiento que se adhieren firmemente a la mayoría de los materiales.
Se pueden obtener altas tasas de resistencia después de la eliminación de grasa y partículas sueltas, por ejemplo, óxido, de las superficies a unir.
Sin embargo, cuando se requiere la máxima resistencia y durabilidad a largo plazo. Se recomienda encarecidamente un pretratamiento superficial.
El tipo de preparación de la superficie se lleve a cabo antes de la unión depende de las prestaciones previstas (Figuras 18, 19 y 20), las condiciones de servicio de la unión y consideraciones económicas (relación costes / beneficios).
+34 93 474 66 66 | antala@antala.es
www.antala.es
Araldite surface preparation and pretreatments. Antala Ltd.Antala Ltd.
+44 161 494 1345 | info@antala.co.uk
www.antala.co.uk
Bonding performances are always a combination of multiple
factors, such as mechanical, chemical or electrostatic
interactions. Bonding is a matter of interface, as the adhesive
has to adhere well to the substrates to be bonded. Therefore,
the surface conditions of the parts to be bonded are a critical
factor in achieving a dependable quality bond.
Huntsman industrial adhesives are high performance
adhesives which adhere firmly to most materials. High
strength bonds can be obtained after removal of grease and
loose particles, e.g. rust, from the surfaces to be joined.
However, when maximum strength and long-term durability
are required, a more thorough mechanical or a chemical
surface pretreatment is highly recommended.
The type of surface preparation to be carried out prior to
bonding depends on the expected performances (Figures
18, 19 and 20), the service conditions of the assembly and
economic considerations (ratio costs / benefits).
Interra presentation for mechanical activities Ayman bolty
the ppt describe briefley how INTERRA operates its activities in Egypt, and other sectors also how it define the sort of failure to activate the proper repair condition by variety of techniques & skilled labours
The presentation covers various aspects of coating and deposition process in detail. The topics that are mainly covered in this PPT are
1) Type of Coating
2) Advantages and limitation for various coating process
3) Figures of various coating process
These processes are sometimes referred to as post-processing. They play a very important role in the appearance, function and life of the product. Broadly, these are processes that affect either a thin layer on the surface of the part itself, or add a thin layer on top of the surface of the part. There are different coating and surface treatments processes, with different applications, uses, etc. The important uses include:
• Improving the hardness
• Improving the wear resistance
• Controlling friction, Reduction of adhesion, improving the lubrication, etc.
• Improving corrosion resistance
• Improving aesthetics
9.1. Mechanical hardening of the surface
These methods apply mechanical impulses (e.g. light hammering) on the surface of a metallic part. This hammering action causes tiny amount of plastic flow on the surface, resulting in the work-hardening of the surface layer due to the introduction of compressive residual stresses. Examples of these processes include Shot peening (uses tiny balls of metal or ceramic), Water-jet peening (uses a jet of water at high pressures, e.g. 400 MPa), or Laser peening (surface is hit by tiny impulses from a laser) – an expensive process used to improve fatigue strength of jet fan blades and turbine impellers.
Another method is explosive hardening, where a layer of explosive coated on the surface is blasted – the resulting impact results in tremendous increase in the surface hardness. This method is used to harden the surface of train rails.
9.2. Case hardening
This is a very common process that is used to harden the outer surface of parts such as gear teeth, cams, shafts, bearings, fasteners, pins, tools, molds, dies etc. In most of these types of components, the use involves dynamic forces, occasional impacts, and constant friction. Therefore the surface needs to be hard to prevent wear, but the bulk of the part should be tough (not brittle); this is achieved best by case hardening. There are several types of case hardening: in most cases, the chemical structure of the metal is changed by diffusing atoms of an alternate element which results in alterations to the micro-structure on the crystals on the surface.
Rolling contact bearings are also known as anti-friction bearing due to its low friction characteristics between ball and inner and outer rings. Rolling contact bearings are used for radial load, thrust load and combination of these both loads. Rolling contact bearings are often used due to its lower price, less maintenance cost and easy to operate.
Comparing Evolved Extractive Text Summary Scores of Bidirectional Encoder Rep...University of Maribor
Slides from:
11th International Conference on Electrical, Electronics and Computer Engineering (IcETRAN), Niš, 3-6 June 2024
Track: Artificial Intelligence
https://www.etran.rs/2024/en/home-english/
Observation of Io’s Resurfacing via Plume Deposition Using Ground-based Adapt...Sérgio Sacani
Since volcanic activity was first discovered on Io from Voyager images in 1979, changes
on Io’s surface have been monitored from both spacecraft and ground-based telescopes.
Here, we present the highest spatial resolution images of Io ever obtained from a groundbased telescope. These images, acquired by the SHARK-VIS instrument on the Large
Binocular Telescope, show evidence of a major resurfacing event on Io’s trailing hemisphere. When compared to the most recent spacecraft images, the SHARK-VIS images
show that a plume deposit from a powerful eruption at Pillan Patera has covered part
of the long-lived Pele plume deposit. Although this type of resurfacing event may be common on Io, few have been detected due to the rarity of spacecraft visits and the previously low spatial resolution available from Earth-based telescopes. The SHARK-VIS instrument ushers in a new era of high resolution imaging of Io’s surface using adaptive
optics at visible wavelengths.
Multi-source connectivity as the driver of solar wind variability in the heli...Sérgio Sacani
The ambient solar wind that flls the heliosphere originates from multiple
sources in the solar corona and is highly structured. It is often described
as high-speed, relatively homogeneous, plasma streams from coronal
holes and slow-speed, highly variable, streams whose source regions are
under debate. A key goal of ESA/NASA’s Solar Orbiter mission is to identify
solar wind sources and understand what drives the complexity seen in the
heliosphere. By combining magnetic feld modelling and spectroscopic
techniques with high-resolution observations and measurements, we show
that the solar wind variability detected in situ by Solar Orbiter in March
2022 is driven by spatio-temporal changes in the magnetic connectivity to
multiple sources in the solar atmosphere. The magnetic feld footpoints
connected to the spacecraft moved from the boundaries of a coronal hole
to one active region (12961) and then across to another region (12957). This
is refected in the in situ measurements, which show the transition from fast
to highly Alfvénic then to slow solar wind that is disrupted by the arrival of
a coronal mass ejection. Our results describe solar wind variability at 0.5 au
but are applicable to near-Earth observatories.
Seminar of U.V. Spectroscopy by SAMIR PANDASAMIR PANDA
Spectroscopy is a branch of science dealing the study of interaction of electromagnetic radiation with matter.
Ultraviolet-visible spectroscopy refers to absorption spectroscopy or reflect spectroscopy in the UV-VIS spectral region.
Ultraviolet-visible spectroscopy is an analytical method that can measure the amount of light received by the analyte.
A brief information about the SCOP protein database used in bioinformatics.
The Structural Classification of Proteins (SCOP) database is a comprehensive and authoritative resource for the structural and evolutionary relationships of proteins. It provides a detailed and curated classification of protein structures, grouping them into families, superfamilies, and folds based on their structural and sequence similarities.
Earliest Galaxies in the JADES Origins Field: Luminosity Function and Cosmic ...Sérgio Sacani
We characterize the earliest galaxy population in the JADES Origins Field (JOF), the deepest
imaging field observed with JWST. We make use of the ancillary Hubble optical images (5 filters
spanning 0.4−0.9µm) and novel JWST images with 14 filters spanning 0.8−5µm, including 7 mediumband filters, and reaching total exposure times of up to 46 hours per filter. We combine all our data
at > 2.3µm to construct an ultradeep image, reaching as deep as ≈ 31.4 AB mag in the stack and
30.3-31.0 AB mag (5σ, r = 0.1” circular aperture) in individual filters. We measure photometric
redshifts and use robust selection criteria to identify a sample of eight galaxy candidates at redshifts
z = 11.5 − 15. These objects show compact half-light radii of R1/2 ∼ 50 − 200pc, stellar masses of
M⋆ ∼ 107−108M⊙, and star-formation rates of SFR ∼ 0.1−1 M⊙ yr−1
. Our search finds no candidates
at 15 < z < 20, placing upper limits at these redshifts. We develop a forward modeling approach to
infer the properties of the evolving luminosity function without binning in redshift or luminosity that
marginalizes over the photometric redshift uncertainty of our candidate galaxies and incorporates the
impact of non-detections. We find a z = 12 luminosity function in good agreement with prior results,
and that the luminosity function normalization and UV luminosity density decline by a factor of ∼ 2.5
from z = 12 to z = 14. We discuss the possible implications of our results in the context of theoretical
models for evolution of the dark matter halo mass function.
2. Wear
Wear is the undesirable removal of
solids from a sliding or rolling
component.
3. Wear analysis
In analyzing a wear problem in a machine,
it is necessary to determine the kind of
wear that occurred.
Analysis requires microscopic examination
of the worn area and a close look at the
used lubricant.
Wear is generally proportional to the
applied load and the amount of sliding.
5. 1.Adhesive Wear
Adhesive Wear — the removal of material due to
adhesion between surfaces.
1. – Mild adhesion — is the removal of surface films,
such as oxides, at a low rate.
2. – Severe adhesion — the removal of metal due to
tearing, breaking, and melting of metallic junctions.
This leads to scuffing or galling of the surfaces and
even seizure.
6. 1.1.Adhesive Wear -Prevention
MECHANICAL
1. Reduce load, speed
and temperature
2. Improve oil cooling
3. Use compatible
metals
4. Apply surface
coatings such as
phosphating
LUBRICANT
1. Use more viscous
oil to separate
surfaces
2. Use "extreme
pressure" (anti-scuff)
additives
such as a sulfur-phosphorous
or
borate compounds
7. 2.Abrasive Wear
• Abrasive Wear — the cutting of furrows on a
surface by hard particles, (for example,
sand particles between contact surfaces, or
hard asperities on an opposing surface).
Hard coatings can reduce abrasive wear.
8. 2.1.Abrasive Wear-Prevention
MECHANICAL
1. Remove abrasive by
improved air and oil
filtering, clean oil
handling practices,
improved seals, flushing
and frequent oil changes
2. Minimize shot peening,
beading, or sand blasting
of surfaces because
abrasives cannot be
completely removed
3. Increase hardness of
metal surfaces
LUBRICANT
1. Use oil free of
abrasive particles
2. Use more viscous
oil
9. 3.Erosion Wear
• Erosive Wear — the cutting of
furrows on a surface by hard particles
contained in a fluid traveling at high
velocity.
10. 3.1.Erosion Wear -Prevention
MECHANICAL
1. Remove abrasive by
improved air and oil
filtering, clean oil
handling practices,
improved seals, flushing
and frequent oil changes
2. Reduce impact angle to
less than 15 degrees
3. Increase hardness of
metal surfaces
LUBRICANT
1. Use oil free of abrasive
Particles
2. Use more viscous oil
11. 4.Polishing Wear
• Polishing Wear — the continuous removal
of surface films, laid down via a chemical
reaction from an additive in oil or by very
fine hard particles in the lubricant, and so
on.
Polishing wear is characterized by very
shiny, very smooth, mirror like metal
surfaces. Fine abrasives wear away the
surface films as they form and reform.
13. 5.Contact fatigue
• Contact Fatigue — the cracking,
pitting, and spalling of a surface in
sequence due to cyclic stresses in a
contact.
Contact fatigue is most common in
rolling element bearings, gear teeth,
and cams.
14. 5.1.Contact fatigue- Prevention
MECHANICAL
1. Reduce contact
pressures and
frequency of cyclic
stress.
2. Use high quality
vacuum melted
steels.
3. Use less abusive
surface finish
LUBRICANT
1. Use clean, dry oil.
2. Use more viscous
oil
3. Use oil with
higher-pressure
viscosity coefficient
15. 6.Corrosive wear
• Corrosive Wear — the removal of
corrosion products from a surface by
motion, such as the rubbing off of
rust.
16. 6.1.Corrosive wear-Prevention
MECHANICAL
1. Use more corrosion
resistant metal
(not stainless)
2. Reduce operating
temperature
3. Eliminate corrosive
material
LUBRICANT
1. Remove corrosive
material such as
too chemically
active additive and
contaminates
2. Use improved
corrosion inhibitor
3. Use fresh oil
17. 7.Electro-Corrosive wear
• Electro-Corrosive Wear — the
removal of metal by dissolution in a
corrosive liquid with the aid of electric
currents.
One source of currents is streaming
potential from high velocity fluids.
The oil serves as the electrolyte.
18. 7.1.Electro-Corrosive wear-prevention
MECHANICAL
1. Decrease liquid
velocity and
velocity gradients
2. Use corrosion-resistant
metals
3. Eliminate stray
currents
LUBRICANT
1. Decrease or
increase electrical
conductivity of
lubricants or
hydraulic fluids
19. 8.Fretting wear
• Fretting Wear — localized wear of
lubricated surfaces due to
reciprocating sliding of extremely low
amplitude because of vibration.
20. 8.1.Fretting wear -Prevention
MECHANICAL
1. Reduce or stop
vibration by tighter
fit or higher load .
2. Improve lubrication
between surfaces by
rougher (then
honed) surface finish
LUBRICANT
1. Use oil of lower
viscosity
2. Relubricate
frequently
3. Use oxidation
inhibitors in oil
21. 9.Electrical discharge wear
• Electrical Discharge Wear — the
removal of molten metal from
surfaces due to electrical sparks
between them.
High static voltages are sometimes
generated by large rotating
machinery and these are relieved by
sparking to regions of lower potential.
22. 9.1.Electrical discharge wear-
Prevention
MECHANICAL
1. Improve electrical
insulation of bearings
2. Degauss magnetic
rotating parts
3. Install brushes on
shaft
4. Improve machine
grounding
LUBRICANT
1. Use of oil of higher
electrical conductivity
23. 10.Cavitation damage
• Cavitation Damage — the removal of
material due to cracking and pitting caused
by high energy implosions of vacuous
cavities in a cavitating liquid.
Liquids cavitate when suddenly subjected
to low pressures.
Removal of metal by vapor cavity implosion
in a cavitating liquid.
24. 10.1.Cavitation damage-Prevention
MECHANICAL
1. Use hard, tough
metals, such as tool
steel
2. Reduce vibration, flow
velocities and
pressures
3. Avoid restriction and
obstructions to liquid
flow
LUBRICANT
1. Avoid low vapor
pressure, aerated, wet
oils
2. Use noncorrosive oils
25. 11.False Brinelling
• False Brinelling — localized wear in
lubricated rolling element bearings
due to slight rocking motion of rollers
against raceways.