Vacuum Response Characteristics in Vacuum- Assisted Countergravity Casting for A206 Alloy

摘要

The foundry industry has focused their efforts on improving casting quality and productivity while addressing the need to produce lightweight, high-strength and thin-wall castings. One casting method that has demonstrated industrial potential for producing clean, thin-wall castings is the vacuum-assisted, countergravity casting process. Because of the scarcity of information regarding the processing attributes of this method, the foundry industry has not fully adopted this resourceful technique in the production of high-quality castings. In this paper, the response characteristics of a variety of vacuum profiles were investigated to assist the foundry industry in understanding the importance of process control for countergiavity vacuum-assisted filling. It was concluded that variables to consider in designing an optimal vacuum profile are the solidification characteristics of the casting alloy, casting weight, casting geometry, casting configuration, superheat temperature and overall metallostatic height. With this knowledge, adaptation and optimization of vacuum-assisted countergravity casting can be realized to obtain the maximum benefits of the process.