1. The reason for the shrinkage and shrinkage phenomenon of aluminum alloy die-casting parts: There is only one reason for the shrinkage and shrinkage phenomenon of die-casting parts, that is, the phase which must exist when the liquid melt is filled into a solid phase after the metal melt is filled. Variable shrinkage. Since the solidification characteristics of the die casting are from the outside to the inside, when the wall thickness of the casting is large. The problem of shrinkage and shrinkage is inevitable inside. Therefore, in the case of die-casting parts, especially for thick die-casting parts, the problem of shrinkage is inevitable and cannot be solved.
2. Two ways of feeding: There are two ways to supplement the casting. One is natural feeding and the other is mandatory feeding. In order to achieve natural feeding, in our casting process system, there must be a process that can achieve "sequential solidification". Many people intuitively believe that the low-pressure casting method can solve the shrinkage and shrinkage defects of the casting, but the fact This is not the case. Using the low-pressure casting process does not mean that the shrinkage and shrinkage defects of the casting can be solved. If the low-alloy die-casting process system does not have the process of feeding, then the low-pressure casting method is produced. The blank is also likely to have a defect of shrinkage and shrinkage by 100%.
Precision Aluminum CNC Machining Part
Due to the characteristics of the die-casting process itself, it is difficult and complicated to set up a natural "sequential solidification" process. The most fundamental reason maybe that
The "sequential solidification" process measures always require a relatively long solidification time for the casting, which is somewhat contradictory to the die casting process itself. The most important feature of forced solidification is that the solidification time is short, generally only one quarter or less of the "sequential solidification". Therefore, on the basis of the die casting process system, the mandatory feeding process is added, and the die casting process is The characteristics of the process are suitable, which can solve the problem of shrinkage and shrinkage of die-casting parts.
3. The only way to solve the shrinkage and shrinkage defects of aluminum alloy die-casting parts: the problem of shrinkage and shrinkage of die-casting parts cannot be completely solved from the die-casting process itself. To solve this problem completely, it can only surpass the process, or from the system. Seeking solutions outside. What is this method?
From the principle of the process, solving the shrinkage and shrinkage defects of castings can only be carried out according to the process idea of feeding. The phase change shrinkage of the casting solidification process is a natural physical phenomenon. We cannot reverse the law of this natural phenomenon, but only follow its laws to solve this problem.
4, the two degrees of forced feeding: extrusion and forging and shrinking: to achieve the mandatory feeding of castings can reach two degrees. One is the basic degree that can eliminate the shrinkage and shrinkage defects of the casting, and the other is the extent to which the inside of the blank can reach the broken grain or forged structure. If we want to use different words to express these two different degrees, then the former can be expressed by "squeezing and feeding", the latter, we can use "forging and feeding" to express. One concept that needs to be fully noticed is that the concept of supplementation is a direct means that cannot be done indirectly. In the process we can have a process parameter to express, this is the "compensation pressure".
Our company also sells CNC Milling Machine Parts at the same time. Welcome everyone to consult.