1 proposed to distinguish between casting and die casting forging (liquid forging), at least two units of manufacturers:
First, some of the middle of the country, including parts and the entire factory. They undertake parts and components, and then find some domestic manufacturers in the country. Because the two blank the production process each are not identical, the present market price is not the same, the latter offer general than the former. If does not distinguish between these two kinds of blank, undertake business quotation in such as pressure casting of the lowest reported out, there will be an error, affects the benefit or even a loss; the second is a professional manufacturer of castings and forgings. Because the latter is a pressure casting, you can use the traditional die casting process, the business will be connected down. In the open die, finally basically due to the die casting process for the production of blank shrinkage shrinkage defects or defect in appearance, blank is unqualified, ultimately resulting in a undue losses.
2 the relationship between die casting die forging, liquid die forging and continuous casting process
Continuous casting even forging process of the nature is in a device, in the same set of mold, the casting of the filling and forging continuously. Continuous casting process is not a new technology, it has a long history of the principle of. The most typical and the most simple continuous casting even forging process, is our familiar liquid die forging (melt forging process). And die forging process, the image that is a degree of automation higher special equipment to produce structure and common die casting as complex liquid die forging. Because of this, die casting die forging and common die casting parts in appearance, we are not easy to come out. And continuous casting process is similar to the quality of the blank, is the "first cast after the forging" process. After the first casting forging process we are very common: blank production to a total of two sets of mold, a used in manual ordinary metal casting, another set for use friction press or hydraulic press finish forging. Die forging process is only in recent years in the international rise of the process, due to the limitation of patent technology, the technology in our country also does not see more. Zhaoqing Guangdong Hong Yin mechanical and Electrical Technology Co., Ltd. is the first introduction of this technology to foreign production. Now produce including sports car forging piston, a small cylinder, extreme sports motorcycle frame (6061 material), a small wheel hub, a variety of blank.
3 introduction of die casting process
Die casting die forging process is a special die forging machine on the completion of the process. The basic process is: the liquid metal first low speed or high speed casting filling into the mold cavity, mold cavity surface, it with liquid metal cooling process pressure forging, which eliminate the blank of shrinkage cavity and porosity defects, also make the blank internal organization achieve forging state of crushing grain. The comprehensive mechanical properties of the blank are improved remarkably. Also produced in the process of blank, outer surface smooth degree reached level 7 (Ra1.6), such as cold extrusion process or machined out of the surface, with a metallic luster. So we will die forging process is called "limit forming process", than the "no cutting and less margin forming process a step further. Die forging process and a advantage is that in addition to the traditional production casting materials. It can also use deformation alloy, forging alloy to produce the parts of the structure is very complex. These include: aluminum alloy, aluminum alloy forging Aluminum Alloy, such as LY11, LY12, 6061, 6063, LYC, LD etc.). The tensile strength of these materials, than the conventional cast alloy high nearly doubled, for aluminum alloy car wheels, a vehicle frame, etc., hoping to resistance to impact materials for the production of components for higher intensity, more positive significance.
4 how to distinguish between these two kinds of blank
From the shape, we are very difficult to distinguish between these two kinds of process produced blank. If you see a processed part, it is even more difficult to distinguish. So, we can only reversed analysis and judgment: one is die casting is generally "structure", and die casting die forgings is "function". "Structure", and "function" is relative. The latter usually involves withstand impact, high temperature, the pressure and the strength of (force), as well as to surface treatment (such as anodic oxidation), heat treatment (solid fusion reinforcement). Typical products are engine cylinder, wheel hub, piston, connecting rod, brake hoof, gas or hydraulic valve body (such as the common three through five of the valve. The former is such as the door frame, instrument panel, engine cover, etc.. Two is to judge from the material composition. Because the die castings are generally foundry alloy, alloy for other brands, is often used in the production of die forging process. Three is from the blank on the outer surface of the processing requirements to determine. Such as aluminum die castings, due to the presence of silicon and for die casting process for production of blank, outer surface have microscopic pores (commonly known as "watermark"). This material anodized surface will have "black spots". Therefore, the blank, such as the requirement of anodic oxidation, then this kind of blank will not be produced by ordinary die casting process. Four is to judge from the metallographic structure. It is easy to distinguish between die casting and die forging in the metallographic. The former is a dendrite as cast microstructure, and the latter is a forging microstructure of uniform broken grains.
5 eliminate some wrong ideas
We have been unable to think with vacuum die casting of infiltration, to solve the die casting of shrinkage cavity and porosity defects, can not think can use vacuum die casting process, the production to continuous casting and forging process to produce function to. When the technology has been progress, we have to keep the pace of scientific attitude and ideological concept. Two is the vacuum die casting parts and common die castings