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TiNi形状记忆合金由于具有优异的超弹性和形状记忆效应等性能而被大量地应用于工业生产中。然而,形状记忆合金的传统加工相当复杂。因此,研究TiNi形状记忆合金的电火花线切割加工(WEDM)性能。采用L27正交阵列以尽量减少实验。在不同的脉冲持续时间、脉冲关断时间、伺服电压、冲洗压力和线速度条件下进行实验。为同步优化提出一种利用Taguchi设计与实用理念的多响应优化方法。通过对信噪比(S/N)的均值分析和方差分析,确定最佳参数水平。Taguchi分析表明:1μs脉冲持续时间、3.8μs脉冲关断时间、40 V伺服电压、1.8×105Pa冲洗压强和8 m/min线速度,有利于同时使材料去除率最大化和表面粗糙度最小化。TiNi形状记忆合金电火花线切割加工的优化结果表明:脉冲持续时间显著影响材料去除率和表面粗糙度。在较长的脉冲持续时间时,在加工表面可观察到放电坑、微裂纹和重铸层。
TiNi shape memory alloys have been widely used in industrial production due to their excellent properties such as super-elasticity and shape memory effect. However, the traditional processing of shape memory alloys is rather complicated. Therefore, the WEDM performance of TiNi shape memory alloys was studied. L27 orthogonal array to minimize the experiment. Experiments were performed under different pulse durations, pulse off time, servo voltage, rinse pressure and line speed. For the synchronous optimization, a multi-response optimization method using Taguchi’s design and practical concept is proposed. Through the average signal to noise ratio (S / N) analysis of variance and analysis of variance, to determine the optimal parameter level. Taguchi analysis shows that: 1μs pulse duration, 3.8μs pulse off time, 40V servo voltage, 1.8 × 105Pa rinse pressure and 8m / min line speed, while helping to maximize material removal and minimize surface roughness. The optimization results of WEDM in TiNi shape memory alloy show that the pulse duration significantly affects the material removal rate and surface roughness. At longer pulse durations, discharge pits, micro-cracks, and recast layers were observed on the machined surface.