The document discusses various casting processes and defects. It describes the functions of gating systems which include providing uniform feed of molten metal to the mould cavity. It also explains the components of gating systems such as pouring basins, sprues, runners and gates. Risering systems are discussed as are common casting defects like shifts, warpage, swell and blowholes along with their causes and remedies. Shell moulding, die casting, and centrifugal casting processes are also summarized.
...
Slush Casting is a traditional method of permanent mold casting process, where the molten metal is not allowed to completely solidify in the mold. When the desired thickness in obtained, the remaining molten metal in poured out. Slush casting method is an effective technique to cast hollow items like decorative pieces, components, ornaments, etc.
APPLICATIONS
Some casting of pewter is cast using slush casting method. Using pewter and other metals mainly hollow products are casted. Decorative and ornamental objects that are casted are as vase, bowls, candlesticks, lamps, statues, jewelery, animal miniatures, various collectibles etc. Small objects and components for industry like tankard handle, handles for hollow wares, etc.
ADVANTAGES
Slush casting is used to produce hollow parts without the use of cores
The desired thickness can be achieved by pouring our the left over molten metal
A variety of exquisitely designed casting can be casted for decorative and ornamental purpose.
Introduction to casting, Major classifications of casting, Casting terminology, Characteristics of molding sand, Constituents of foundry sand, Patterns and their types, Cores and types of cores, Gating system, Types of gates, Solidification, Riser system, Types of riser, Types of allowances, Directional Solidification, Defects in casting, Riser design(Chvorinov's rules), Advanced casting techniques:Shell molding, Permanent mould casting, Vacuum die casting, Low pressure die casting, Continuous casting, Squeeze casting, Slush casting, Vacuum casting, Die Casting, Centrifugal casting, Investment casting
...
Slush Casting is a traditional method of permanent mold casting process, where the molten metal is not allowed to completely solidify in the mold. When the desired thickness in obtained, the remaining molten metal in poured out. Slush casting method is an effective technique to cast hollow items like decorative pieces, components, ornaments, etc.
APPLICATIONS
Some casting of pewter is cast using slush casting method. Using pewter and other metals mainly hollow products are casted. Decorative and ornamental objects that are casted are as vase, bowls, candlesticks, lamps, statues, jewelery, animal miniatures, various collectibles etc. Small objects and components for industry like tankard handle, handles for hollow wares, etc.
ADVANTAGES
Slush casting is used to produce hollow parts without the use of cores
The desired thickness can be achieved by pouring our the left over molten metal
A variety of exquisitely designed casting can be casted for decorative and ornamental purpose.
Introduction to casting, Major classifications of casting, Casting terminology, Characteristics of molding sand, Constituents of foundry sand, Patterns and their types, Cores and types of cores, Gating system, Types of gates, Solidification, Riser system, Types of riser, Types of allowances, Directional Solidification, Defects in casting, Riser design(Chvorinov's rules), Advanced casting techniques:Shell molding, Permanent mould casting, Vacuum die casting, Low pressure die casting, Continuous casting, Squeeze casting, Slush casting, Vacuum casting, Die Casting, Centrifugal casting, Investment casting
Hot forming processes, such as die-casting, investment casting, plaster casting, and sand casting, each provide their own unique manufacturing benefits. Comparing both the advantages and disadvantages of the common types of casting processes can help in selecting the method best suited for a given production run.
This PPT will let you know about metal casting and more specifically about the type of casting that is, Die casting, types of die casting, Cleaning of castings and inspection of casting
Saudi Arabia stands as a titan in the global energy landscape, renowned for its abundant oil and gas resources. It's the largest exporter of petroleum and holds some of the world's most significant reserves. Let's delve into the top 10 oil and gas projects shaping Saudi Arabia's energy future in 2024.
Final project report on grocery store management system..pdfKamal Acharya
In today’s fast-changing business environment, it’s extremely important to be able to respond to client needs in the most effective and timely manner. If your customers wish to see your business online and have instant access to your products or services.
Online Grocery Store is an e-commerce website, which retails various grocery products. This project allows viewing various products available enables registered users to purchase desired products instantly using Paytm, UPI payment processor (Instant Pay) and also can place order by using Cash on Delivery (Pay Later) option. This project provides an easy access to Administrators and Managers to view orders placed using Pay Later and Instant Pay options.
In order to develop an e-commerce website, a number of Technologies must be studied and understood. These include multi-tiered architecture, server and client-side scripting techniques, implementation technologies, programming language (such as PHP, HTML, CSS, JavaScript) and MySQL relational databases. This is a project with the objective to develop a basic website where a consumer is provided with a shopping cart website and also to know about the technologies used to develop such a website.
This document will discuss each of the underlying technologies to create and implement an e- commerce website.
Industrial Training at Shahjalal Fertilizer Company Limited (SFCL)MdTanvirMahtab2
This presentation is about the working procedure of Shahjalal Fertilizer Company Limited (SFCL). A Govt. owned Company of Bangladesh Chemical Industries Corporation under Ministry of Industries.
Hybrid optimization of pumped hydro system and solar- Engr. Abdul-Azeez.pdffxintegritypublishin
Advancements in technology unveil a myriad of electrical and electronic breakthroughs geared towards efficiently harnessing limited resources to meet human energy demands. The optimization of hybrid solar PV panels and pumped hydro energy supply systems plays a pivotal role in utilizing natural resources effectively. This initiative not only benefits humanity but also fosters environmental sustainability. The study investigated the design optimization of these hybrid systems, focusing on understanding solar radiation patterns, identifying geographical influences on solar radiation, formulating a mathematical model for system optimization, and determining the optimal configuration of PV panels and pumped hydro storage. Through a comparative analysis approach and eight weeks of data collection, the study addressed key research questions related to solar radiation patterns and optimal system design. The findings highlighted regions with heightened solar radiation levels, showcasing substantial potential for power generation and emphasizing the system's efficiency. Optimizing system design significantly boosted power generation, promoted renewable energy utilization, and enhanced energy storage capacity. The study underscored the benefits of optimizing hybrid solar PV panels and pumped hydro energy supply systems for sustainable energy usage. Optimizing the design of solar PV panels and pumped hydro energy supply systems as examined across diverse climatic conditions in a developing country, not only enhances power generation but also improves the integration of renewable energy sources and boosts energy storage capacities, particularly beneficial for less economically prosperous regions. Additionally, the study provides valuable insights for advancing energy research in economically viable areas. Recommendations included conducting site-specific assessments, utilizing advanced modeling tools, implementing regular maintenance protocols, and enhancing communication among system components.
Welcome to WIPAC Monthly the magazine brought to you by the LinkedIn Group Water Industry Process Automation & Control.
In this month's edition, along with this month's industry news to celebrate the 13 years since the group was created we have articles including
A case study of the used of Advanced Process Control at the Wastewater Treatment works at Lleida in Spain
A look back on an article on smart wastewater networks in order to see how the industry has measured up in the interim around the adoption of Digital Transformation in the Water Industry.
Water scarcity is the lack of fresh water resources to meet the standard water demand. There are two type of water scarcity. One is physical. The other is economic water scarcity.
3. Functions of gating system
• Gate is defined as one of the channels which actually lead into the mould
cavity, and the term Gating or gating system refers to all channels by means
of which molten metal is delivered to the mould cavity
• Functions
1. To provide continuous, uniform feed of molten metal, with less errors as
possible to the mould cavity.
2. To supply the casting with liquid metal at best location to achieve proper
directional solidification and optimum feeding of shrinkage cavities.
3. To fill the mould cavity with molten metal in the shortest possible time to
avoid temperature gradient.
4. 4. To provide with a minimum of excess metal in the gates and risers.
5. To prevent erosion of the mould walls.
6. To prevent slag, sand and other foreign particles from entering the mould.
5. Gating and risering system
• Gating system : casting system provides all passageways to the casting,
through which the molten metal passes to the cavity.
6. Components of gating system
Pouring basin:
• This part of the gating system is made on or in the top of the mould.
Sometimes, a funnel-shaped opening which serves as pouring basin is made
at the top of the sprue in the cope.
• The main purpose of the pouring basin is to direct the flow of metal from
ladle to the sprue, to help maintaining the required rate of liquid metal flow,
and to reduce errors and at the sprue entrance.
7. Sprue:
• The vertical passage that passes through the cope and connects the pouring
basin with the runner or gate is called the sprue.
• The cross-section of a sprue may be square, rectangular, or circular.
Runner:
• In large castings, molten metal is usually carried from the sprue base to
several gates around the cavity through a passageway called the runner.
• The runner is generally preferred in the drag, but it may sometimes be
located in the cope, depending on the shape of the casting.
• It should be streamlined to avoid aspiration and turbulence.
8. Gate
• A gate is a passage through which molten metal flows from the runner to
the mould cavity.
• The location and size of the gates are so arranged that they can feed liquid
metal to the casting at a rate consistent with the rate of solidification.
• A gate should not have sharp edges as they may break during passage of
the molten metal.
• However, the gates should be located where they can be easily removed
without damaging the casting.
9. Risering System
• A riser or a feeder head is a passage of sand made in the cope to permit the
molten metal to rise above the highest point in the casting after the mould
cavity is filled up.
• Risers serve a dual function:
1) they compensate for solidification shrinkage which is a very common
casting defect.
2) a heat source so that they freeze last and promote directional solidification.
• Risers provide thermal gradients from a remote chilled area to the riser.
• If the metal does not appear in the riser, it indicates that the mould cavity has
not been completely filled up.
12. • Shell is a special form of sand casting. This process is relatively recent and
because of its advantages it is being increasingly used
• Shell moulding process is applicable to production of castings ranging from
about 250 gram to about 25 kilogram in ferrous as well as non-ferrous
metals and alloys.
• The sand used in this method is a mixture of the following ingredients:
a) Dry fine silica sand and
b) Synthetic resin binder 3 to 10 % by weight.
13. • Resins used are the phenol formaldehydes, urea formaldehydes, alkyds and
polyesters in the form of fine powder.
• The resins must be thermosetting plastics because , the strength obtained
after the mould is heated & must be retained when molten metal is poured.
• The mould is formed from a mixture of fine sand (100-150 mesh) and a
thermosetting resin binder that is placed opposite to heated pattern.
• In actual practice, the metal pattern is heated to about 200 to 300 °C, the
melting point of resin
• Then after a silicon parting agent is sprayed on the surface, the resin &
sand mixture is deposited on the pattern by blowing or dumping.
14. • The resin starts melting and, in a few seconds, forms together with the sand
a uniform resin-soaked layer of about 4 to12 mm in thickness, depending
on the heating period.
• The pattern is then turned over to allow the unbounded sand to be removed,
leaving the shell on the pattern.
• The shell is then stripped mechanically and once more heated for 3 to 5
minutes in a special oven to cure the plastic material.
15. • In this way, stable shell moulds are obtained which are made in two
sections. Both sections are matched and joined by guides to obtain the
casting mould.
• Finally, they are placed in a metal case, and surrounded by about 37 mm of
steel shot, sand, and other backup material to support them during pouring.
• Applications
1. Cylinders for air-cooled engines with tapered fins
2. cams,
3. camshafts
4. air compressor crank cases
5. pistons and piston rings
16. Advantages
1. Floor space required per ton of castings is less compared to conventional
castings.
2. Operators can be trained easily, thus, providing more output per operator.
3. Skilled operators are not required.
4. The process can be highly mechanised.
18. Pressure die casting.
• Die: shaping device
• Die casting: casting which can be made by using metal dies.
• Die casting is the art to produce accurately dimensioned parts by
forcing molten metal under pressure into split metal dies which resemble a
common type of permanent mould.
• Because of the low temperature of the die (it is water-cooled), the casting
solidifies quickly, then die parts to be separated and the casting ejected.
• If the parts are small, several parts may be cast at one time in what is known as
multiple cavity die.
• This process is particularly suitable for lead, magnesium, tin, and zinc alloys.
19. Types
• Two main types of machines are used to produce die castings
(1) the hot chamber die casting
(2) the cold chamber die casting machine
22. working / Process
• In a hot chamber submerged plunger-type machine, the plunger operates in
one end of a gooseneck casting which is submerged in the molten metal.
• With the plunger in the upper position, metal flow by gravity into this
casting through holes, just below the plunger and the entrapped liquid metal
is forced into the die through the gooseneck channel and in-gate.
• As the plunger retracts, the channel is again filled with the right amount of
molten metal.
• The plunger made of refractory material may be operated manually or
mechanically and hydraulically, that is by means of air pressure below 150
kgf/cm2 (about 15 MN/m2).
• Heating is continued throughout the operation to keep the molten metal
sufficiently liquid.
24. Working /process
• In a horizontal plunger cold-chamber machine, the plunger is driven by air
or hydraulic pressure to force the charge into the die.
• As soon as the ladle is emptied, plunger moves to the left and forces the
metal into the cavity . After the metal solidified, the core is withdrawn, and
then the die is opened.
• Ejectors are employed to remove the casting automatically from the die.
25. Advantages of die casting are:
1. Very high rate of production is achieved.
2. Close dimensional tolerances of the order of ± 0.025 mm is possible.
3. Surface finish of 0.8 microns can be obtained.
4. Very thin sections of the order of 0.5 mm can be cast.
Disadvantages of this process are:
1. Not economical for small runs.
2. Only economical for nonferrous alloys.
3. Heavy castings cannot be cast
4. Cost of die and die casting equipment is high.
26. Centrifugal casting
• In the centrifugal casting, molten metal is poured into moulds while they are
rotating.
• The metal falling into the centre of the mould at the axis of rotation is thrown
out by the centrifugal force under sufficient pressure towards the periphery, and
the impurities present being lighter in weight are also pushed towards the
centre.
• Solidification progresses from the outer surface to inwards, thus developing an
area of weakness in the centre of the wall.
• The use of gates, feeders, and cores is eliminated, making the method less
expensive and complicated.
• Centrifugal casting can be classified into three general types:
true centrifugal, semi centrifugal, and centrifuged.
27. True centrifugal casting
• This employs, moulds made up of steel (with a refractory mould wash
or even a green or dry sand lining) or of graphite. Which are rotational
symmetric.
• The melt is poured while the mould rotates at its axis, which may be
horizontal, vertical or inclined at any suitable angle between 0 to 90°,
although horizontal axis of rotation is a more common practice
28. • While rotating, the molten metal is carried to the walls of the cavity by
centrifugal force as shown in fig.
• The metal then solidifies forms a hollow casting without the use of a
central core.
• The outside of the mould is water-cooled to accelerate solidification
• This method is ideal for hollow cylindrical castings such as bushings, cast
iron pipes, etc.
29. Centrifuged
• In this process, several identical or nearly similar moulds are located
radially about a vertically arranged central riser or sprue or gate.
• which feeds the metal into the cavities through a number of radially gates.
30. • The entire mould is rotated with the central sprue which acts as the axis of
rotation. Thus, it is not a purely centrifugal process.
• This type of casting is suitable for small, intricate parts where feeding
problems are encountered.
31. Defects
• Causes And Remedies
1. Shifts. This is an external defect in a casting.
Cause:
• Due to core misplaced or mismatching of top and bottom parts of the
casting usually at a parting line.
• Misalignment of flasks is another likely cause of shift.
Remedy:
• By ensuring proper alignment of the pattern or die part,
• moulding boxes, correct mounting of patterns on pattern plates, and
• checking of flasks, locating pins, etc. before use.
32. 2. Warpage.
Warpage is unintentional and undesirable deformation in a casting that
occurs during or after solidification.
Cause:
• Due to different rates of solidification at different sections of a casting
• Large and flat sections or intersecting sections such as ribs are particularly
prone to warpage.
Remedy:
• to produce large areas with wavy, corrugated construction, or add sufficient
ribs or rib-like shapes,
• to provide equal cooling rates in all areas.
• a proper casting design can go a long way in reducing the warpage of the
casting.
33. 3. Swell.
• A swell is an enlargement of the mould cavity by metal pressure,
Cause: This is caused by improper or defective ramming of the mould.
Remedy: To avoid swells, the sand should be rammed properly and evenly.
4. Blowholes.
• Blow holes are smooth, round holes appearing in the form of a cluster of a large number of small
holes below the surface of a casting.
• These are entrapped bubbles of gases with smooth walls.
Cause:
• Excessive moisture in the sand.
• Sand grains are too fine.
• Sand is rammed too hard.
Remedy:
• To prevent blowholes, the moisture content in sand must be well adjusted.
• Sand of proper grain size should be used.
• Ramming should not be too hard.
34. 5. Drop.
• A drop occurs when the upper surface of the mould cracks, and pieces of
sand fail into the molten metal.
Cause:
• This is caused by low strength and soft ramming of the sand,
• insufficient fluxing of molten metal and insufficient reinforcement of sand
projections in the cope.
Remedy:
• The above factors are eliminated to avoid drop.