1. Differentiating the meaning of the pressure casting and die casting (liquid forging) parts:
1, is a number of domestic agencies, including parts and the entire manufacturer. They undertake external parts and components, and then find some manufacturers in the country. Since the production processes of the two blanks are different, the current market price is not the same, and the latter is generally higher than the former. If you do not distinguish between the two types of roughs, if you press down on the casting at a low price when undertaking business quotation, there will be operational mistakes, which will affect the efficiency and even loss.
2, is a professional manufacturer of castings and forgings. Because the latter is die-casting, it can be manufactured using traditional die-casting technology and the business can be taken over. After the die-casting mold was opened, the billet produced by the die-casting process finally had a shrinkage shrinkage defect or an appearance defect, and the blank was unqualified, eventually causing undue loss.
2. The relationship between die forging, liquid forging and continuous casting and forging processes:
The essence of the continuous casting and forging process is the continuous completion of casting styling and forging in a single set of tools on a single machine. The continuous casting and forging process is not a new process, and its principle has a long history. The most typical and simplest continuous casting and forging process is the familiar liquid forging (melt forging) process. The die-casting and forging process, graphically speaking, is a kind of specialized equipment that uses a higher degree of automation to produce liquid forgings that are as complex as ordinary die castings. Because of this, die-casting forgings and ordinary die-castings are not easy to separate in appearance. The quality of the blank produced by the continuous casting and forging process is similar to that of the "cast first and then forged" process. The first forging and forging processes are very common: two blanks are needed for the blank production, one for manual ordinary metal casting, and the other for precision forging using a friction press or a hydraulic press. The die-casting forging process is an internationally emerging process in recent years. Due to the limitation of patented technology, this process is still rare in China. Guangdong Zhaoqing Hongyin Electromechanical Technology Co., Ltd. is the earliest introduction of this technology to foreign production. A variety of blanks including sports car forging pistons, small cylinders, extreme sports motorcycle frame (6061 material), and small wheel hubs have been produced.
3. Die Casting Forging Process Description:
The die-casting forging process is a process that is completed on a dedicated die-casting forging machine. Its basic process is: metal liquid is firstly filled into the mold cavity at a low speed or high speed. The mold has a movable cavity surface. It presses and forges with the cooling process of the molten metal to eliminate the shrinkage shrinkage of the blank. Loose defects also make the internal structure of the blank reach the forged broken grains. The overall mechanical properties of the blank have been significantly improved. In addition, the blank produced by this process has an outer surface finish of 7 (Ra1.6), and has a metallic luster like a cold extrusion process or a machined surface. Therefore, we call the die-casting forging process an "extremely-shaped forming process", which is a step further than "no cutting and less excess forming process". Another advantage of the die-casting die forging process is that, in addition to producing conventional casting materials, it can also use deformed alloys and forged alloys to produce very complex parts. These alloy grades include: hard aluminum super hard aluminum alloy, wrought aluminum alloy, such as LY11, LY12, 6061, 6063, LYC, LD, etc.). The tensile strength of these materials is almost twice as high as that of ordinary cast alloys. It is of more positive significance for aluminum alloy automobile wheels, frames, and other parts that are expected to be produced with higher-strength and impact-resistant materials.
4. How to distinguish the two blanks:
From the appearance, it is difficult for us to distinguish the blanks produced by these two processes. If you see a machined part, it's even harder to tell. Therefore, we can only reverse the analysis and judgment: First, die castings are generally "structural parts", while die-casting die forgings are "functional parts." "Structure" is relative to "feature". The latter generally refers to to withstand the impact, high temperature, pressure, strength (force), and to surface treatment (such as anodizing), heat treatment (Solid-melting strengthening) and so on. Typical products are engine blocks, hubs, pistons, connecting rods, brake shoes, pneumatic or hydraulic valve bodies (such as the common three-position five-way valve). The former are such as door frames, instrument panels, and engine covers. The second is to judge from the material composition. Because die castings are generally cast alloys, for other grades of alloys, die casting and die forging processes are often used. The third is to judge from the processing requirements of the blank on its outer surface. Such as aluminum die castings, due to containing silicon, and the blank produced by the die casting process, the surface of the microscopic pores (commonly known as "water pattern"), the surface of this material after the anodizing will have "black spots." Therefore, if blanks require anodizing, such blanks will not be produced by ordinary die casting processes. The fourth is to judge from the metallographic organization. Die-casting and die-casting die forgings are very easy to distinguish on metallography. The former is a dendritic as-cast structure, and the latter is a forged structure of uniformly broken grains.
5. Eliminate some wrong ideas:
1. We cannot think that vacuum impregnation after die-casting can solve the shrinkage shrinkage and shrinkage defects of die castings, nor can we think that the vacuum die-casting process can be used to produce functional parts that can be produced by continuous casting and forging. When the technology in the industry has progressed, we must have a scientific attitude that advances with the times in terms of ideas and ideas. 2, vacuum die castings and ordinary die castings, there are the same shrinkage shrinkage defects; vacuum die casting, it is just a bit more than ordinary die casting in the auxiliary process of the process, the shrinkage due to the liquid metal shrinkage With shrinkage (its interior is vacuum, no gas), it is no way. Third, the most common mistake that professionals make is that although it is known that this blank can not be produced by ordinary die-casting technology, it is a process called “indirect and partial extrusion of reverse punch”. They think that this process has the same effect as the liquid forging process. This is completely wrong. The essence of the “reverse punch extrusion” process is still a die-casting process. Only the type of “full forward projection punch forging” is the real liquid forging process.
6. Summary:
It is very meaningful to distinguish between ordinary die castings and die casting forgings. Although the method to be mastered is not difficult, many of them are concepts and cognitive skills.
