基于响应面法的铝合金间接挤压铸造工艺研究

Indirect Squeeze Casting Process of Aluminum Alloy Based on Response Surface Method

为研究间接挤压铸造工艺,选取ZL101铝合金,以孔隙率为指标,首先通过单因素实验,分析了挤压压力、模具温度与比例系数3个因素对孔隙率的影响。然后采用Box-Behnken实验设计方法来设计响应面实验,建立了间接挤压铸造工艺参数与孔隙率相互关系的预测模型,方差分析结果表明,实验结果和数学模型拟合良好。通过对各个因素交互作用的响应面进行分析,得知模具温度和挤压压力对孔隙率的影响存在显著的交互作用,模具温度和比例系数、比例系数和挤压压力对孔隙率的影响不存在显著的交互作用。通过对环形件浇注系统的直浇道边缘部位进行金相检测分析,得知由于压力的施加,会使已经凝固的金属壳层发生不均匀的塑性流动。

In order to study indirect squeeze casting process, ZL101 aluminum alloy was selected with porosity as indicators and the effects of process parameters of pressure, die temperature and proportionality factor on porosity were analyzed. Box-Behnken design of the experiment was developed to design response surface experiment and regression model of the relationship between the indirect squeeze casting process parameters and porosity was established. ANOVA result shows that the fitting effect between the experimental results and the mathematical model is good. The effect of die temperature and pressure on porosity has certain interaction; however, there is not significant interaction for the effect of die temperature and proportionality factor or the effect of proportionality factor and pressure on porosity by analyzing response surface of interaction of various factors. Due to the applied pressure, uneven plastic flow happens in the congealed metal shell by metallographic testing of the edge of sprue in gating system parts.