再利用镍铬钛烤瓷合金的铸流性及元素分析

Castability and elemental analysis of the reused Ni-Cr-Ti alloy

目的:探讨再利用镍铬钛烤瓷合金的表面处理方法及回收料含量对铸流性的影响,观察铸件金相结构并分析其元素构成。方法:在回收料含量一定条件下,比较不同表面处理方法对铸流率的影响;在同一表面处理方法条件下,比较不同回收料含量对铸流率的影响。观察分析铸件金相结构及表面元素构成比。结果:经喷砂或Inconel合金酸洗液酸洗的再利用合金铸流率较高;再利用合金中回收料含量应控制在62.5%或以下;再利用合金铸件金相结构及表面元素构成比与新合金铸件基本相似。结论:经过适当处理的再利用镍铬钛烤瓷合金具有较好的铸流性,所得铸件金相结构及元素构成改变不大。

Objective： To investigate the effects of different methods of surface treatment as well as different weight ratios of reused Ni-Cr-Ti alloys on the castability and to analyze the metallography and elemental composition of casting surfaces, Methods： 3 groups of Ni-Cr-Ti alloys containing 50% reused materials, one treated by sandblasting with the other two pickled with acid combinations for Inconel alloy and Nimonic alloy respectively, were cast into sieve patterns to calculate the castability value （CV）, Then the castability of alloys containing 0%, 50%, 62,5%, 75%, 87.5%, 100% reused materials was evaluated with the same method. Metallographies of the castings were observed and elemental analyses were performed with EDS/SEM. Results： CVs of reused alloys treated by sandblasting or pickling with the acid combination for Inconel alloy were higher than the other. And the CVs of alloys oontaining reused materials less than 75% were significantly higher than alloys containing 75% or more reused materials. Metallographies of castings made from reused alloys were similar to that of castings made of new alloys. With the growth of reused alloys weight ratio, the amounts of Ti, Al, Si decreased while the amount of S and other minor elements increased. But the changes were generally minimal. Conclusion： The proper treatment for Ni-Cr-Ti alloys was sandblasting or pickling with right acid combinations. The weight ratio of reused alloys should be not higher than 75%. Castings made from new alloys and that made from reused alloys had similar metallography and elemental composition.