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Showing posts with label Casting. Show all posts
Showing posts with label Casting. Show all posts

Formation Of Technology Basics

Forming Technology Developments
The history of the formation of metal began in prehistoric times that estimated in the span of time between the years 4000 to 3000 BC The development of metal formation begins in the manufacture of accessories or decorations royal, shield for war purposes, household appliances and so on. Materials metallic material is generally made of bronze and brass. Process for the manufacture of equipment that is carried out is done manually by a process of heat and cold. Metal forming processes for a wide range of equipment is done by experts who have specialized skills metals. Experts metal has a hand job skills (handy craft) obtained from generation to generation. The process of formation of profile shapes is done entirely by hand using the skills. Auxiliary equipment used include various forms of hammers, foundations and models forming a simple mold. Profile shape plates produced from this formation process have high artistic value, particularly in the form of engraving that is displayed on the product. Profiles are shown to have meaning and value of art by displaying forms of, flowers, symbols, human civilization as well as profiles of animals. Some of the results of historical relics found household appliances such as forms cup / saucer, a variety of dishes. Product plates and cups have special designs and carvings that have meaning and value of art. Archaeological field survey results illustrate that household products are used for different kingdoms with products issued for ordinary people. Usually these products have specific characteristics, ranging from design and engraving or embellishment on the product. Patterns or profile shapes worked for jewelery or accessories for this kingdom has a high artistic level, it can be seen from some historical relics found in several historical museums in France and other historical towns. The development of metal forming technology is characterized by the discovery process of the formation by using the tools forming by using a pressure hydraulic system, also using the runway, punch, swage, dies as a tool to form the desired profiles. If at first the formation process is done manually on top of the foundations of forming with a hammer, then now is the process of formation is done with a variety of methods. The method used in metal forming process including the process of bending or kinking, squeezing, rolling, spinning, deed, drawing, stretching, crumping, blanking, press and so on. Each process has its own formation ability, for example for the bending process, the process is able to bend it straight and neat plates used for office equipment such as file cabinets, lockers, cabinets of data and so on. Plate rolling process is also very widely used for decision-making of pipes, tanks, pressure vessels such as boiler or boilers and others. This rolling products also can be done manually or with a motor control. Propulsion motor control is easier in the process of rolling, rolling pelatpelat particularly thick with high level of accuracy. The rapid expansion also occurs in the process of formation of the pressure or press. Press process is performed using hydraulic power using a swage or mold with a pressure rubber (rubber) forming. This process can be done in a cold state, especially for the working of the formation of thin plates. The results of this press products can form a hard profiles, with the resulting shape with no defects. Process pressure (press) is widely used for the hydraulic body formation-body car with the term now full press body. Plates sheets are experiencing this formation work as press produces plates become more stiff (rigid). Plate products produced are also experiencing rapid development, it is since the discovery of plate rolling process which produces plates that have formability, weldability and capable machine. Plate products resulting from the process of rolling this multilevel mempuyai microstructure elongated shape and flat, so that the plate is the result of rolling or bending elastic properties memunyai good to do the process of formation. Plates quality sheet has the characteristics of good formability. These properties appear if the plates undergo a process of formation of the side plate experiencing stretching does not cause cracks. These cracks can cause damage or tearing of the plate components are formed. Characteristic properties of weldability can also be shown if the plate undergoing a process of welding the cracks or crack does not occur in the transition area. The transition area is an area that is susceptible to damage because this area is an area that experienced a change of heat and cold. The term welding technology is the Heat Affect Zone (HAZ), which in this area microstructure formed erratic changes. Due to changes in the microstructure of this, then there is a change of the mechanical properties of the plate material. Changes in mechanical properties, especially on the nature of violence and tension luluhnya. Plate material products produced not only for the purposes of its creation only diproduk but plate products are used for special purposes can also be generated. Plate products for special purposes is usually for military purposes are also used for banking keperluaan. Plate products for military purposes can be seen from the manufacture of steel tanks used for war purposes. Tank Steel produced has a bullet-proof characteristics, so that the plate material used must be resistant to various kinds of gunfire. Bulletproof vests used by the security forces are also coated with a material bulletproof plate. Bulletproof plate material used to coat the front of the chest or has a very thin thickness when compared with the plates used for Tank Steel.
 
     Basic Engineering Establishment
Metal forming technique is a process that is done by providing a change in the shape of the workpiece. These shape changes can be done by giving the external force causing plastic deformation. This metal forming applications can be seen in several examples such as rolling (rolling), bending (bending), forging (forging), extrusion (extruding), withdrawal of wire (wire drawing), the withdrawal of the (deep drawing), and others. Steps being taken in the process of formation of a construction include:
1. Design tools according to function and usefulness.
2. Analyze the construction of the loading plate
3. Make the design drawings
4. Determine the type of plate material
5. Determine methods of grafting and reinforcement
6. Determine the method of assembly
7. Creating a tool construction working drawings
8. Creating a stretch image
9. Perform initial cuts (pre-cutting)
10. Perform cutting plate material
11. Conducting the process of formation
12. Determine the tools or models
13. The method of assembly
14. Measurement of the dimensions of the construction
15. The test construction
16. Finishing
Adult formation technology is widely used for various purposes. Construction is usually distinguished by the formation of the desired dimensions.

         Basic Metal Casting
The process of casting (casting) is one of the techniques of making a product where the metal melted in a crucible then poured into the mold cavity which is similar to the original shape of the cast product to be made. Casting can also be interpreted as a manufacturing process that uses liquid metal and molds to produce parts with a form that approximates the shape of the final geometry of the finished product. Casting process itself can be divided into two kinds, namely traditional casting (traditional) and non-traditional (non-traditional).
Traditional techniques consist of:
1. Sand-Mold Casting
2. Dry-Sand Casting
3. Shell-Mold Casting
4. Full-Mold Casting
5. Cement-Mold Casting
6. Vacuum-Mold Casting
While non-traditional techniques are divided into:
1. High-Pressure Die Casting
2. Permanent Mold Casting-
3. Centrifugal Casting
4. Plaster Mold Casting-
5. Investment Casting
6. Solid-Ceramic Casting
There are four factors that affect or are characteristic of the casting process, namely:
1. The flow of molten metal into the molding cavity
2. There was a heat transfer during solidification and cooling of the metal in the mold
3. Effect of printed material
4. Freezing of molten metal from the condition
Classification is based on the age of the casting mold, there are casting with disposable (expendable mold) and no permanent mold casting (permanent mold). Expendable sand molds included in the mold. Therefore can only be used one time casting alone, after which the mold is destroyed when making the casting. In mold making, the types of sand used was silica sand, zircon sand or green sand. While the adhesive between the grains of sand can be used, bentonite, resins, furan or water glass. as follows:
1. Cavity (mold cavity), is the room where the molten metal is poured into the mold. The shape of the cavity is equal to the workpiece to be casted. Cavity mold made using a pattern.
2. Core (core), its function is to create a cavity in the casting. The core is made separately with mold and assembled at the time of the mold will be used.
3. Gating system (system inlet), an inlet of the mold kerongga descending channel.
4. Sprue (channel down), an inlet from the outside to the vertical position. This channel can also be more than one, depending on the desired casting speed.
5. Pouring basin, the grooves on the mold whose main function is to reduce the speed of the liquid metal goes directly from the ladle into the sprue. High speed metal flow may occur in the sprue erosion and the transport of liquid metal impurities originating from the furnace kerongga mold.
6. Raiser (enhancer), a useful reserve of liquid metal in the mold cavity to fill back in case of shrinkage due to solidification. The metals that can be used to perform the casting process, namely: Cast iron, white cast iron, gray cast iron, cast iron maliable, nodular cast iron, cast steel and others. Metal smelting is the most important aspect in casting operations as a direct effect on the quality of the cast product. In the smelting process, first charge consisting of metal, alloying elements and other materials such as flux and slag forming elements inserted into the furnace. Flux is the inorganic compound that can "clean up" the molten metal by removing gases dissolved participate and also elements of impurity (impurities). Flux has beberpa usability depends on molten metal, such as aluminum alloys are cover fluxes (which prevents oxidation of the aluminum surface of the liquid), Cleaning fluxes, drossing fluxes, refining fluxes, and dry wall fluxes. Smelting furnaces used in the foundry industry is an electric arc furnace, induction furnace, furnace crucibles, and a cupola furnace.

Four Factors that Affect

There are 4 factors that affect or are characteristic of the casting process, namely:

1. The flow of molten metal into the molding cavity
2. There was a heat transfer during solidification and cooling of the metal in the mold
3. Effect of printed material
4. Freezing of molten metal from the condition.

Classification is based on the age of the casting mold, there are casting with disposable (expendable mold) and no permanent mold casting (permanent mold). Expendable sand molds included in the mold. Therefore can only be used one time casting alone, after which the mold is destroyed when making the casting. In mold making, the types of sand used was silica sand, zircon sand or green sand. While the adhesive between the grains of sand can be used, bentonite, resins, furan or water glass. as follows:
1. Cavity (mold cavity), is the room where the molten metal is poured into the mold. The shape of the cavity is equal to the workpiece to be casted. Cavity mold made using a pattern.
2. Core (core), its function is to create a cavity in the casting. The core is made separately with mold and assembled at the time of the mold will be used.
3. Gating system (system inlet), an inlet of the mold kerongga descending channel.
4. Sprue (channel down), an inlet from the outside to the vertical position. This channel can also be more than one, depending on the desired casting speed.
5. Pouring basin, the grooves on the mold whose main function is to reduce the speed of the liquid metal goes directly from the ladle into the sprue. High speed metal flow may occur in the sprue erosion and the transport of liquid metal impurities originating from the furnace kerongga mold.
6. Raiser (enhancer), a useful reserve of liquid metal in the mold cavity to fill back in case of shrinkage due to solidification. The metals that can be used to perform the casting process, namely: Cast iron, white cast iron, gray cast iron, cast iron maliable, nodular cast iron, cast steel and others. Metal smelting is the most important aspect in casting operations as a direct effect on the quality of the cast product. In the smelting process, first charge consisting of metal, alloying elements and other materials such as flux and slag forming elements inserted into the furnace. Flux is the inorganic compound that can "clean up" the molten metal by removing gases dissolved participate and also elements of impurity (impurities). Flux has beberpa usability depends on molten metal, such as aluminum alloys are cover fluxes (which prevents oxidation of the aluminum surface of the liquid), Cleaning fluxes, drossing fluxes, refining fluxes, and dry wall fluxes. Smelting furnaces used in the foundry industry is an electric arc furnace, induction furnace, furnace crucibles, and a cupola furnace.

Basic Metal Casting

The process of casting (casting) is one of the techniques of making a product where the metal melted in a crucible then poured into the mold cavity which is similar to the original shape of the cast product to be made. Casting can also be interpreted as a manufacturing process that uses liquid metal and molds to produce parts with a form that approximates the shape of the final geometry of the finished product. Casting process itself can be divided into two kinds, namely traditional casting (traditional) and non-traditional (non-traditional).

Traditional techniques consist of:
1. Sand-Mold Casting
2. Dry-Sand Casting
3. Shell-Mold Casting
4. Full-Mold Casting
5. Cement-Mold Casting
6. Vacuum-Mold Casting

While non-traditional techniques are divided into:
1. High-Pressure Die Casting
2. Permanent Mold Casting-
3. Centrifugal Casting
4. Plaster Mold Casting-
5. Investment Casting
6. Solid-Ceramic Casting

IMPORTANT POINTS to DIE CASTING


Die casting mould integrates such know how and technology as casting, mould cooling, and further, cast finishing methods.
Die cast products are used in various field, including areas related to automotive engines, house ware, toys, life style tools. In the future, die cast products will need to be ever more precise, durable, and economical with shorter delivery times. The key to these improvements is mould design, including casting methods, and casting technology.

Design of Die Casting
It has been well established that in a simple die casting die the injected stream travels across the cavity and impinges on opposite wall. It then spreads out along  the cavity wall and finally backfills the entire cavity. In complex dies or those with cores, the flowing mass is more turbulent. This concept of cavity filling is basic to the proper design of these dies.

Gate Location and Size
For a given casting there are many workable gating designs, each more or less approaching the prevailing conditions. In general, a gate is usually placed on an edge from which it can be cleanly sheared, or where its trimming will not impair the casting surface. But gate location also affects the character of the metal flow, hence porosity and surface finish.
One authority advocates a gate at the smallest cross section of the die cavity so that the surface of the casting increases with increasing distance from the gate. This technique creates a better heat balance within the die ; the hotter metal contacts the die surfaces of smaller area and transfers less heat to the die. As the metal flows farther, it cool and transfers less per unit area to the die.  Thus, the total heat input to the die block is more uniform throughout the cavity.
                                                    
Vents
Porosity is most likely to occur where vents are too small or so poorly located that they became blocked by the inflowing metal. To prevent this, some vents should be located as close to the gate as possible to allow air to escape from that part of the cavity which fills last.
Test have shown that venting has an important bearing on the injection speed and casting quality. They indicated that the speed of the entering jet is seldom equal to that of a free jet. When the vents were sealed, the jet velocity was reduced by 50%, and increased injection pressure will not increase filling time unless adequate is provided.
Vents should not exceed about 0.008 in. thickness if fins are to be avoid, but commercial practice uses vents up to 0.016 in. deep. Ejection pin, slides, insert clearances, and the parting line all add to the total cavity venting are. Some designers use a vent area of at least 50% of the ingate area.

Runner
Runner design and locations can be varied to meet the needs of conservation or dissipation of heat to maintain thermal equilibrium and appropriate die temperature gradients, Shapes of runner cross sections vary from round to trapezoidal to elliptical; from wide and flat to narrow and thick. If the heat transfer ate of the runner system high, high surface area to volume ratio, the metal is cooled somewhat by the time it reaches the gate. This is advantage for a casting of thick cross section but is poor practice for a thin walled casting because the metal will lose more heat traveling within the cavity, and incomplete fusion and deep striation are likely. In such case, the heat transfer between the runner and cavity can be altered by using a runner more nearly circular in cross section.
In practice most die casting runners are trapezoidal, about two times as wide as they are deep. As they approach a round or square cross section, internal porosity is more likely to appear.

Sprue Pin
In edge gate cavities, which are typical of cold chamber machines, the sprue is merely a small appendage to the main runner and has little influence on metal floe or thermal equilibrium within the die . In center gate dies for zinc, however, the sprue may have considerable influence on the thermal balance within a die block. Heat transfer from the sprue depends upon the contact area between the sprue pin and the cast metal. A slender sprue pin present a small heat absorption mass and consequently, because of friction, the sprue pin tip may reach temperatures equal to or greater than the injection temperature of molten alloy. This impedes solidifications at the gate. Therefore, it is better to use a well splayed sprue of large diameter in conjunction with a blunt conical sprue pin.  Thus, an adequate cross section can be maintained with a relatively thin walled sprue. This design allow the sprue o water cooled, so a better die block temperature gradient can be maintained because a large proportion of heat dissipated from the injected metal  is absorbed by the spue pin an less passes to the adjacent die cavity.

Materials
Die casting materials must be resistant to thermal shock, softening, and erosion at elevated temperatures. Of lesser importance are heat treatability, machinability, weldability, and resistance to heat checking. The performance of die materials is direcly related to the injection temperature of the molten alloy, the thermal gradients within the die, and the production cycle. Tool steels of increasing alloy content are required as the injection temperature of the molten alloy and the thermal gradients within the die increase, and the production cycle becomes shorter. Dies  for use with zinc can be prehardened by the manufacturer in a range of Rc 29-34. The higher melting alloy require hot work tool steel.

hopefully the above can make inputs, and technical development of the world is more excited, thank you for your attention.

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DIE CASTING INTRODUCTION


Generally one can say the diecasting process consists of 4 main region:

+ die casting machine
+ casting alloy
+ die
+ periperal equipment around the diecasting machine to mechanise the proses.

Considerable new developments have taken place during the past years in the regions of diecasting machine,alloys and peripheral equipment,however quality demands on the castings also dicatate increased.The ever increasing considerable effort has been spent in this area.As a proof,one may of die construction.

For the diecasting of suitable light or heavy metal alloy we have the following machine types available:

+ the horizontal cold chamber system
+ the horizontal cold chamber system for centre gating
+ vertical cold chamber system
+ the hot chamber system
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THE PRESSURE DIE CASTING
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A. Planing Stage
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Casting Pressures for Die Casting Alloy
Standart Part :
Al+Mg to 400 bar
Zn 100-200 bar
Ms : 300-400 bar
Technical Part :
Al+ Mg 400-600 bar
Zn : 200-300 bar
Ms : 400-500 bar
Pressure Tight Part :
Al+ Mg 800-1000 bar
Zn : 250-400 bar
Mg : 800-1000 bar
Electro Plating Parts :
Zn 220-250 bar.
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B. Design Stage
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Fs (kn) = A (cm2) x p (bar ) /100
F (kn) = 1,1-1,25 x (Fs+F1)
F1(kn) = tangential x Fk(kN)
A= Project Area (cm2)
F1 = Slide Force (Kn)
p = Spec Casting Pressure (bar)
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DIE STEELS
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Working Life
Insert Piece :
Al 100.000
Zn 300.000-500.000
Ms Brass 35.000
Small Piece :
Al 50.000
Zn 150.000
Brass 18.000
Shot Sleeve :
Al 80.000
Zn 500.000
Ms Brass 70.000
Plunger :
Al 20.000
Zn 100.000
Ms Brass 20.000
Nozlee :
Zn 250.000
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A. Heat Treatment
Recomendaions for the Hardening of Die Casting Dies
Die Plate :
Zink-Alloys 43-45 HRC
Al-Alloys 44-46 HRC
Al-,Mg-Alloys 44-46 HRC
Cu-Alloys 39-40 HRC
Insert :
Zink -Alloys 43-45 HRC
Al-Alloys 44-46 HRC
Al-Mg-Alloys 44-46 HRC
Cu-Alloys 39-40 HRC
Split Insert/Machining After/Heatreatment :
Zink-Alloys 41 HRC
Al-Alloys 43-45 HRC
Al-Mg-Alloys 43-45 HRC
Cu-Alloys 34-36 HRC
Round Core :
Zink-Alloys 46 HRC
Al-Alloys 46 HRC
Al-Mg-Alloys 48 HRC
Cu-Alloys 43 HRC
Cavity Core :
Zink-Alloys 43 HRC
Al-Alloys 44-46 HRC
Al,Mg-Alloys 44-46 HRC
CU-Alloys 36-37 HRC
Sprue Buhs/Speader :
Zink-Alloys 48 HRC
Al-Alloys 48 HRC
Al,Mg-Alloys 48 HRC
Cu-Alloys 39-40 HRC
Slide /Wedge Lock/Guides :
Zink-Alloys,Al-Alloys,Al-,Mg-Alloys =Case Hardening
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B. Diecasting Dies Built From Standart
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DIE TEMPERATURE CONTROL
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A. Practical Hints
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GATING TECHNIQUE FEED SYSTEMS
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A. General Rules
B. Centre Gatint System For Horizontal Cold Chamber Machine
C. 3-Plate System With Stripper plate Built In Die
D. 3-Plate System With Stripper Plate Built In Machine
E. System Loss And Gating Calculations
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DIE TRIAL
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A. Entry Inspection
B. Testing
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DIE MAINTENANCE



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