TC4钛合金表面污染层金相检验参数优选

Parameters Optimization of Metallographic Examination of Contamination Layer on TC4 Titanium Alloy Surface

摘要: 采用正交试验法和逼近于理想值的排序方法（TOPSIS）对TC4钛合金表面污染层的金相检验参数进行综合评价，根据评价结果选出了最优抛光工艺和最优浸蚀剂。结果表明：磨样工艺参数对制样质量的影响程度依次为：压力 > 抛光机转速 > 抛光时间，磨样工艺参数的最优组合为：磨样机转速300 r·min^-1、抛光时间1 min、压力30 N。最优浸蚀剂为，先使用体积分数为2%的HF （质量浓度：40%～42%）+体积分数为4%的HNO₃（质量浓度：65%～68%）+H₂O（余量），再使用质量浓度为2%的NH₄HF₂水溶液。

Abstract: The metallographic examination parameters of TC4 titanium alloy surface contamination layer were evaluated by orthogonal experiment and technique for order preference by similarity to ideal solution (TOPSIS). The optimal polishing process and etchant were selected according to the evaluation results. The results show that the influence degree of polishing process parameters on sampling quality was pressure > polishing machine speed > polishing time, the optimal combination of polishing process parameters was grinding prototype speed 300 r·min^-1, polishing time 1 min, pressure 30 N. The optimal etchant was 2% (volume fraction) HF(mass concentration 40%～42%)+4% (volume fraction) HNO₃(mass concenrtation 65%~68%)+H₂O(margin), and then 2% (mass concentration) NH₄HF₂ aqueous solution.