
2007年8月29日星期三
Aluminum Investment Casting
Aluminum Investment Casting we called here is American style silicon gel process(with green wax and better sand) with very good smooth surface, tight tolerance, suitable for small part making widely used for stainless steel. It’s different with Russian style investment casting actually called soluble glass process(with white wax and rough sand)with relative rough surface, bigger tolerance, suitable for large part making more than 1.00KGS especially for carbon steel, alloy steel, sometimes also for ductile iron and grey iron

Aluminium casting foundry
NINGBO INNOVAW MECHANICAL is a professional supplier for casting and machined part which is widely used for Automobile, Medical, earthmover, petroleum, electricity Industry. Dedicating in long-term business with foreign customers from North America and west Europe, we are exactly know what’s the customer requirement when they provide drawings and material specification. And our engineering can suggest the best process and technology to make the component or any design changing if necessary. Most of our products are exported to Canada, USA, and west Europe Germany, France, Italy, Norway, Finland, Switzerland, etc. and win good reputation among our customers.
NINGBO INNOVAW cover different foundry and machining factory based on different casting process: investment casting, sand casting and pressure die casting, gravity casting, as well as precision machining with CNC machines. Our MOTTO is: Quality first, with competitive price and delivery in time. If you need some casting or machined part OEM or aftermarket, INNOVAW will be the best choice for you…
NINGBO INNOVAW cover different foundry and machining factory based on different casting process: investment casting, sand casting and pressure die casting, gravity casting, as well as precision machining with CNC machines. Our MOTTO is: Quality first, with competitive price and delivery in time. If you need some casting or machined part OEM or aftermarket, INNOVAW will be the best choice for you…
2007年8月27日星期一
STEEL CASTING
Casting is a manufacturing process in which molten metal is poured into a mold, allowed to solidify within the mold, and then the mold is broken and the solid piece is taken out. Casting is used for making parts of complex shape that would be difficult or uneconomical to make by other methods.
Steel Casting are especially adapted for parts that must withstand wear, shocks or heavy loads. They are stronger than either wrought iron or cast iron. or malleable iron and are very tough. High alloy Steel castings can be heat treated to bring about the diffusion of carbon or alloying elements, softening, hardening, stress relieving, toughening, improve machinability, increase wear resistance, and removal of hydrogen entrapped at the surface of the casting.
Type of Casting
Plain Carbon Steel Castings
High Alloy Steel Castings
Manganese Steel Castings
Hi Chrome Castings
Ni-Hard Castings
SG Iron Castings
Stainless Steel Castings
Heat Resistant Cast Steel
Steel Casting are especially adapted for parts that must withstand wear, shocks or heavy loads. They are stronger than either wrought iron or cast iron. or malleable iron and are very tough. High alloy Steel castings can be heat treated to bring about the diffusion of carbon or alloying elements, softening, hardening, stress relieving, toughening, improve machinability, increase wear resistance, and removal of hydrogen entrapped at the surface of the casting.
Type of Casting
Plain Carbon Steel Castings
High Alloy Steel Castings
Manganese Steel Castings
Hi Chrome Castings
Ni-Hard Castings
SG Iron Castings
Stainless Steel Castings
Heat Resistant Cast Steel
high pressure die casting
Mould design: Our engineers and technical staff will collaborate with a client's own engineers on the design of low pressure die casting to ensure smooth production and optimum performance of the finished product.
Our engineers designed mould by PRO/ENGINEER, SOLIDWORKS, UNIGRAPHICS and simulation analysis software to be sure the quality and high efficiency before tooling machining. Mould cavity and frame will be machined by automatic CNC milling center, CNC turning lathe, EDM , wire cutting machines. Our experiences and technology will be great helpful for you.
Our engineers designed mould by PRO/ENGINEER, SOLIDWORKS, UNIGRAPHICS and simulation analysis software to be sure the quality and high efficiency before tooling machining. Mould cavity and frame will be machined by automatic CNC milling center, CNC turning lathe, EDM , wire cutting machines. Our experiences and technology will be great helpful for you.

2007年8月25日星期六
alloy die casting
Improper use of aluminium
Improper use of aluminium may result in problems, particularly in contrast to iron or steel, which appear "better behaved" to the intuitive designer, mechanic, or technician. The reduction by two thirds of the weight of an aluminium part compared with a similarly sized iron or steel part seems enormously attractive, but it must be noted that this replacement is accompanied by a reduction by two thirds in the stiffness of the part. Therefore, although direct replacement of an iron or steel part with a duplicate made from aluminium may still give acceptable strength to withstand peak loads, the increased flexibility will cause three times more deflection in the part.
Where failure is not an issue but excessive flex is undesirable due to requirements for precision of location, or efficiency of transmission of power, simple replacement of steel tubing with similarly sized aluminium tubing will result in a degree of flex which is undesirable; for instance, the increased flex under operating loads caused by replacing steel bicycle frame tubing with aluminium tubing of identical dimensions will cause misalignment of the power-train as well as absorbing the operating force. To increase the rigidity by increasing the thickness of the walls of the tubing increases the weight proportionately, so that the advantages of lighter weight are lost as the rigidity is restored.
In such cases, aluminium may best be used by redesigning the dimension of the part to suit its characteristics; for instance making a bicycle frame of aluminium tubing that has an oversize diameter rather than thicker walls. In this way, rigidity can be restored or even enhanced without increasing weight The limit to this process is the increase in susceptibility to what is termed "buckling" failure, where the deviation of the force from any direction other than directly along the axis of the tubing causes folding of the walls of the tubing.
The latest models of the Corvette automobile, among others, are a good example of redesigning parts to make best use of aluminium's advantages. The aluminium chassis members and suspension parts of these cars have large overall dimensions for stiffness but are lightened by reducing cross-sectional area and removing unneeded metal. As a result, they are not only equally or more durable and stiff than the steel parts they replace, but they possess an airy gracefulness that most people find attractive. Similarly, aluminium bicycle frames can be optimally designed so as to provide rigidity where required, yet exhibit some extra flexibility, which functions as a natural shock absorber for the rider.
The strength and durability of aluminium varies widely, not only as a result of the components of the specific alloy, but also as a result of the manufacturing process. This variability, plus a learning curve in employing it, has from time to time gained aluminium a bad reputation. For instance, a high frequency of failure in many poorly designed early aluminium bicycle frames in the 1970s hurt aluminium's reputation for this use. However, the widespread use of aluminium components in the aerospace and high-performance automotive industries, where huge stresses are withstood with vanishingly small failure rates, illustrates that properly built aluminium bicycle components need not be intrinsically unreliable. Time and experience has subsequently proven this to be the case.
Similarly, use of aluminium in automotive applications, particularly in engine parts that must survive in difficult conditions, has benefited from development over time. An Audi engineer, in commenting about the V12 engine--producing over 500 horsepower (370 kW)--of an Auto Union race car of the 1930s that was recently restored by the Audi factory, noted that the engine's original aluminium alloy would today be used only for lawn furniture and the like. As recently as the 1960s, the aluminium cylinder heads and crankcase of the Corvair earned a reputation for failure and stripping of threads in holes, even as large as spark plug holes, which is not seen in current aluminium cylinder heads.
One important structural limitation of an aluminium alloy is its fatigue properties. While steel has a high fatigue limit (the structure can theoretically withstand an infinite number of cyclical loadings at this stress), aluminium's fatigue limit is near zero, meaning that it will eventually fail under even very small cyclic loadings, but for small stresses this can take an exceedingly long time.
Where failure is not an issue but excessive flex is undesirable due to requirements for precision of location, or efficiency of transmission of power, simple replacement of steel tubing with similarly sized aluminium tubing will result in a degree of flex which is undesirable; for instance, the increased flex under operating loads caused by replacing steel bicycle frame tubing with aluminium tubing of identical dimensions will cause misalignment of the power-train as well as absorbing the operating force. To increase the rigidity by increasing the thickness of the walls of the tubing increases the weight proportionately, so that the advantages of lighter weight are lost as the rigidity is restored.
In such cases, aluminium may best be used by redesigning the dimension of the part to suit its characteristics; for instance making a bicycle frame of aluminium tubing that has an oversize diameter rather than thicker walls. In this way, rigidity can be restored or even enhanced without increasing weight The limit to this process is the increase in susceptibility to what is termed "buckling" failure, where the deviation of the force from any direction other than directly along the axis of the tubing causes folding of the walls of the tubing.
The latest models of the Corvette automobile, among others, are a good example of redesigning parts to make best use of aluminium's advantages. The aluminium chassis members and suspension parts of these cars have large overall dimensions for stiffness but are lightened by reducing cross-sectional area and removing unneeded metal. As a result, they are not only equally or more durable and stiff than the steel parts they replace, but they possess an airy gracefulness that most people find attractive. Similarly, aluminium bicycle frames can be optimally designed so as to provide rigidity where required, yet exhibit some extra flexibility, which functions as a natural shock absorber for the rider.
The strength and durability of aluminium varies widely, not only as a result of the components of the specific alloy, but also as a result of the manufacturing process. This variability, plus a learning curve in employing it, has from time to time gained aluminium a bad reputation. For instance, a high frequency of failure in many poorly designed early aluminium bicycle frames in the 1970s hurt aluminium's reputation for this use. However, the widespread use of aluminium components in the aerospace and high-performance automotive industries, where huge stresses are withstood with vanishingly small failure rates, illustrates that properly built aluminium bicycle components need not be intrinsically unreliable. Time and experience has subsequently proven this to be the case.
Similarly, use of aluminium in automotive applications, particularly in engine parts that must survive in difficult conditions, has benefited from development over time. An Audi engineer, in commenting about the V12 engine--producing over 500 horsepower (370 kW)--of an Auto Union race car of the 1930s that was recently restored by the Audi factory, noted that the engine's original aluminium alloy would today be used only for lawn furniture and the like. As recently as the 1960s, the aluminium cylinder heads and crankcase of the Corvair earned a reputation for failure and stripping of threads in holes, even as large as spark plug holes, which is not seen in current aluminium cylinder heads.
One important structural limitation of an aluminium alloy is its fatigue properties. While steel has a high fatigue limit (the structure can theoretically withstand an infinite number of cyclical loadings at this stress), aluminium's fatigue limit is near zero, meaning that it will eventually fail under even very small cyclic loadings, but for small stresses this can take an exceedingly long time.
2007年8月21日星期二
die casting Shrinkage
Castings shrink when they cool. Like nearly all materials, metals are less dense as a liquid than a solid. During solidification (freezing), the metal density dramatically increases. This results in a volume decrease for the metal in a mold. Solidification shrinkage is the term used for this contraction. Cooling from the freezing temperature to room temperature also involves a contraction. The easiest way to explain this contraction is that is the reverse of thermal expansion. Compensation for this natural phenomenon must be considered in two ways.
Solidification Shrinkage
The shrinkage caused by solidification can leave cavities in a casting, weakening it. Risers provide additional material to the casting as it solidifies. The riser (sometimes called a "feeder") is designed to solidify later than the part of the casting to which it is attached. Thus the liquid metal in the riser will flow into the solidifying casting and feed it until the casting is completely solid. In the riser itself there will be a cavity showing where the metal was fed. Risers add cost because some of their material must be removed, by cutting away from the casting which will be shipped to the customer. They are often necessary to produce parts which are free of internal shrinkage voids.
Sometimes, to promote directional solidification, chills must be used in the mold. A chill is any material which will conduct heat away from the casting more rapidly that the material used for molding. Thus if silica sand is used for molding, a chill may be made of copper, iron, aluminum, graphite, zircon sand, chromite or any other material with the ability to remove heat faster locally from the casting. All castings solidify with progressive solidification but in some designs a chill is used to control the rate and sequence of solidification of the casting.
Patternmaker's Shrink (Thermal Contraction)
Shrinkage after solidification can be dealt with by using an oversized pattern designed for the relevant alloy. Pattern makers use special "contraction rulers" (also called "shrink rules") to make the patterns used by the foundry to make castings to the design size required. These rulers are 1 - 6% oversize, depending on the material to be cast. These rulers are mainly referred to by their actual changes to the size. For example a 1/100 ruler would add 1 mm to 100 mm if measured by a "standard ruler" (hence being called a 1/100 contraction ruler). Using such a ruler during pattern making will ensure an oversize pattern. Thus, the mould is larger also, and when the molten metal solidifies it will shrink and the casting will be the size required by the design, if measured by a standard ruler. A pattern made to match an existing part would be made as follows: First, the existing part would be measured using a standard ruler, then when constructing the pattern, the pattern maker would use a contraction ruler, ensuring that the casting would contract to the correct size.
Solidification Shrinkage
The shrinkage caused by solidification can leave cavities in a casting, weakening it. Risers provide additional material to the casting as it solidifies. The riser (sometimes called a "feeder") is designed to solidify later than the part of the casting to which it is attached. Thus the liquid metal in the riser will flow into the solidifying casting and feed it until the casting is completely solid. In the riser itself there will be a cavity showing where the metal was fed. Risers add cost because some of their material must be removed, by cutting away from the casting which will be shipped to the customer. They are often necessary to produce parts which are free of internal shrinkage voids.
Sometimes, to promote directional solidification, chills must be used in the mold. A chill is any material which will conduct heat away from the casting more rapidly that the material used for molding. Thus if silica sand is used for molding, a chill may be made of copper, iron, aluminum, graphite, zircon sand, chromite or any other material with the ability to remove heat faster locally from the casting. All castings solidify with progressive solidification but in some designs a chill is used to control the rate and sequence of solidification of the casting.
Patternmaker's Shrink (Thermal Contraction)
Shrinkage after solidification can be dealt with by using an oversized pattern designed for the relevant alloy. Pattern makers use special "contraction rulers" (also called "shrink rules") to make the patterns used by the foundry to make castings to the design size required. These rulers are 1 - 6% oversize, depending on the material to be cast. These rulers are mainly referred to by their actual changes to the size. For example a 1/100 ruler would add 1 mm to 100 mm if measured by a "standard ruler" (hence being called a 1/100 contraction ruler). Using such a ruler during pattern making will ensure an oversize pattern. Thus, the mould is larger also, and when the molten metal solidifies it will shrink and the casting will be the size required by the design, if measured by a standard ruler. A pattern made to match an existing part would be made as follows: First, the existing part would be measured using a standard ruler, then when constructing the pattern, the pattern maker would use a contraction ruler, ensuring that the casting would contract to the correct size.
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