Foundry Engineering [PDF]

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Assignment No # 1 Topic: Introduction TO New Foundry Techniques



Subject: Foundry Engineering (Met 208)



Session: 2018-22 Submitted By: Muhammad Hasnain Gul



Roll No: MME-18-31



Introduction TO Foundry  A foundry is a factory that produces metal castings.  Foundry is the concept of machinery equipment’s, man power and other power resources.  Metals are cast into shapes by melting them into a liquid, pouring the metal in a mold and removing the mold material or casting after the metal has solidified as it cools.  The most common metals processed area aluminium, bronze, zinc and cast iron.  Foundry contain mainly metal casting, furnaces, molding and other process.  New technologies and techniques enter in foundry and factories.



Types OF Foundry Foundry processes can be divided into two types.  Ferrous Foundries  Non-Ferrous Foundries Foundry processes involve making the mould and the core, melting and pouring the metal into the mould and finally removing the mould and core and finishing the product.



Foundry Technique & Technology Foundry technology is the art and science of the processes and materials used in manufacturing castings from metal and alloys. In metalworking, casting involves pouring liquid metal into a mold, which contains a hollow cavity of desired shape and then allowing it to cool and solidify. Casting is most often used for making complex shapes that would be difficult or uneconomical to make by other methods.



Importance OF Foundry Techniques & Technology  Foundry processes are continuously developing to improve the quality of products and production efficiency, and take advantage of new technologies.  Breakthroughs in development have enabled significant advances in metal casting at key moments in the industry’s history.



Advantages OF Foundry Techniques & Technologies When different techniques and technologies entered in factory then lot of benefits are creates for all of us.     



Less work Less time Low cost machine Less man power Good productivity



Disadvantages OF Foundry Techniques & Technologies There are following disadvantages of foundry techniques and technologies.  More work.  Lot of man power required.  Lot of money for buy machines.  Lot of space occupy old type factory.



Advanced Foundry Technology Parts or components for:  Construction machinery  Housings  Gear manufacture  Plastics processing machinery  Agricultural machinery  Impellers, rollers  Machine bases and beds  Pulleys  Textile technology  Gear cutting machines  Machine tools



Advance Foundry Techniques Some of the latest techniques are described in the following:   



Molding Techniques Injection Molding Blow Molding Compression Molding Casting Techniques Investment Casting Die Casting Lost Foam Casting Centrifugal casting Pattern Making and Core Making Techniques



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Molding Techniques



The first major stage in founding is the production of mould with its impression of the casting and its planned provision for metal flow and feeding. The basic techniques of molding and core production will be reviewed:



- Injection Molding  Injection molding is a manufacturing process for producing parts by injecting molten material into a mould.  Material for the part is fed into a heated barrel, mixed (using a helical shaped screw), and injected into a mould cavity, where it cools and hardens to the configuration of the cavity. It is the latest process developed in the industry of foundry.  Injection molding can be performed with a host of materials mainly including metals, glasses and most commonly thermoplastic and thermosetting polymers.



Injection Molding Machine



- Blow Molding



 Blow molding is a manufacturing process for forming and joining together hollow plastic parts.  It is also used for forming glass bottles or other hollow shapes.  In general, there are three main types of blow molding: extrusion blow molding, injection blow molding, and injection stretch blow molding.



Blow Molding Machine



- Compression Molding



Compression Molding is a method of molding in which the molding material generally preheated, is first placed in an open, heated mould cavity.  The mould is closed with a top force or plug member, pressure is applied to force the material into contact with all mould areas, while heat and pressure are maintained until the molding material has cured.  Compression molding is a high-volume, highpressure method suitable for molding complex, highstrength fiberglass reinforcement.  Advanced composite thermoplastic materials can also be molded by this technique. 



 Casting Techniques Casting is a process in which a liquid metal is poured into a mold to solidify. Different casting techniques are used but modern and advanced are following:



- Investment Casting  Investment casting is an industrial process based on and also called lost-wax casting, one of the oldest known metal-forming techniques. Lost-foam casting is a modern form of investment casting that eliminates certain steps in the process.  The process is generally used for small castings, but has been used to produce complete aircraft door frames, steel castings of up to 300 kg(660 lbs) and aluminium castings of up to 33kg(66 lbs).  It is generally more expensive per unit than die casting or sand casting but has lower equipment costs.  It can produce complicated shapes that would be difficult or impossible with die casting, it requires little surface finishing and only minor machining.



Investment Casting Process



- Die Casting  Die casting is a metal casting process that is characterized by forcing molten metal under high pressure into a mould cavity.  The mould cavity is created using two hardened tool steel dies which have been machined into shape and work similarly to an injection mould during the process.  The essential feature of die casting is the use of permanent metal mold, into which molten alloy is directly poured or injected under pressure, giving rise to the separate processes of gravity and pressure die casting.



 Gravity die casting, also referred to as permanent mould casting, has many features in common with other processes of metal founding including sand casting, both in production technique and in type of product.



Die Casting Process



- Lost Foam Casting  Lost-foam casting is a type of evaporative-pattern casting process that is similar to investment casting except foam is used for the pattern instead of wax.



Lost Foam Casting Process



- Centrifugal Casting  Centrifugal casting or rotocasting is a casting technique that is typically used thin-walled cylinders.  It is typically used to cast materials such as metals, glass, and concrete. A high quality is attainable by control of metallurgy and crystal structure.  The essential feature of centrifugal casting is the introduction of molten metal into a mould which is rotated during solidification of the casting.  The centrifugal force can thus play a part in shaping and in feeding according to the variation of the process employed.



Centrifugal Casting Process



 Pattern Making and Core Making Techniques  In casting, a pattern is a replica of the object to be cast, used to prepare the cavity into which molten material will be poured during the casting process.   Patterns used in sand casting may be made of wood, metal, plastics or other materials.  Core making is the process which forms the interior part of the casting. The mould provides a space for



the molten metal to go, while the core keeps the metal from filling the entire space.  Cores can be used to extend mould projections to create extra mould sections, or to block out and create negative drafts.  Some modern techniques are also developed for core and pattern making.



Molding and Core-Making     



Power operated molding machines High pressure molding machines Core-blowing machine Core drawing machines Continuous core making machines



Advance Foundry Technology Material Handling System  Material handling equipment is equipment that



 



relate to movement, storage, control and protection of materials, goods and products throughout the process of manufacturing, distribution, consumption and disposal. Material handling equipment is the mechanical equipment involved in the complete system. Material handling equipment is generally separated into four main categories: storage and handling equipment, engineering systems, industrial trucks, and bulk material handling.



Sand Preparation and Control  Continuous mixer  Mold ability controller-slotted vibratory feeder  Integrated Systems -Sand preparation with mixed resin sand continuously discharging into a molding box placed on vibratory compaction table, a pattern loop-mould stripping device and a shake out with a reclamation plant.



Melting, Pouring and shakeout equipments  Machineries are deployed depends on factors such as: -Type and condition of equipment -Economical feasibility -Availability of floor space  Automatic pouring system



 Crane, lift truck, turnover truck, belt conveyor  Vibrating type shakeout, Bumber type shakeout



Control of dust and fumes  Fine particles of saw dust in the pattern shop.  When sand is mixed and prepared during molding, shake out, feting operation.  Fumes during melting, metal transfer, pouring operation.  Cyclone, Filter, Electrostatic precipitator, Mechanical collectors, Scrubbers, after burners.



Robotic Automation  Many operations that are performed in a foundry are ideally suited for robotic automation, because they are:  Three D’s - dirty, dangerous and dull.  Three H’s – hot, heavy and hazardous.



‘Unimate’ The first industrial robot  In 1954, inventor George Devol developed a machine, which he called ‘programmed article transfer’ and later it was commercialized under the name ‘Unimate’.  ‘Unimate’ was installed in a die casting operation in 1961 at Ford Motor Company and its main job was to unload hot casting from die- casting machine.



Computers in foundries  Product design and Analysis -Transferring geometric information from human mind to a computer



-FEM (Simulation of stress, Strain, Heat transfer, Fatique, Fracture) -CAM (Simulate machining Operation, Accurate and automatic calculation of geometric properties)  Casting design and simulation -Convert part design to tooling design, showing orientation in the mould, parting line, application of draft and allowances, core boxes.



Software packages for foundry use 



Magmasoft – Optimization casting and foundry processes.



 AutoCAST – Knowledge based system for cast design decision and cast model creation. 



ProCAST – Developed by UES software



- Simulating solidification process  CastCAE – Mould filling and solidification simulation  MeshCAST – Fully automatic 3D mesh generation