充型温度及真空度对真空吸铸A356合金丝材长度的影响

Effect of Filling Temperature and Vacuum Degree on the Length of A356Wire Prepared by Vacuum Suction Casting

采用真空吸铸法制备了A356铝合金丝材,并对充型温度和真空度对丝材长度的影响进行了研究。结果表明,真空度是影响合金丝材长度的主要因素。当充型温度一定时,A356铝合金丝材的吸铸长度随着真空度的减小而增大,并且,当真空度减小到一定程度时,丝材吸铸长度增加幅度减小。当真空度一定时,A356铝合金丝材的吸铸长度随充型温度的升高而增大。优化的充型温度为993~1 023K,真空度为0.034~0.047 MPa。应用Bernoulli方程及传热学原理推导出了丝材的吸铸长度的理论公式。当真空度一定时,丝材的吸铸长度与充型起始温度呈对数关系变化。

Effects of vacuum degree and filling temperature on the casting length of A356 aluminum alloy wire prepared by vacuum suction casting were investigated. The results show that absolute vacuum is di- rectly responsible for the length of A356 aluminum alloy wire. With a given filling temperature, the length of A356 aluminum alloy wire is increased with the decrease of the absolute vacuum. And then, the absolute vacuum is decreased to a certain degree, the increase of the length of the wire is slown down. At a fixed absolute vacuum, the length of the A356 aluminum alloy wire is increased with the in- crease of the filling temperature. The appropriate parameters were presented as follows： absolute vacu- um of 0. 034~0.047 MPa and the filling temperature of 993~1 023 K. Based on Bernoulli equation and principle of heat transfer, theoretical formula for the length of the wire was derived. The length of the wire with the initial filling temperature exhibits logarithmic relation.