再生型壳与ZTC4熔体的界面稳定性

Interfacial stability of regenerated moulds against molten ZTC4 alloy

从研究再生型壳中几种典型金属离子对铸件表面的污染影响规律入手,通过在型壳材料中添加Al、Nb和Mn等金属元素实际浇铸ZTC4合金(Ti-6Al-4V),探讨不同残留金属在铸造过程中对铸件表面质量、陶瓷/钛合金界面成分、组织形貌及显微硬度等的影响,揭示废弃型壳材料中铸造残留金属对钛合金新铸坯陶瓷/合金界面稳定性的影响规律。结果表明:含Al、Nb和Mn等金属残留的型壳浇铸ZTC4合金,铸件表面外观平整无明显铸造缺陷;相比无金属残留型壳,含残留金属型壳的铸件表面粗糙度明显增加;Al金属残留对型壳与熔融钛合金界面稳定性的影响较小,而Nb和Mn金属残留能明显降低型壳与熔融钛合金的界面稳定性,铸件表面粗糙度可以在一定程度上反映界面稳定性;当型壳中含有Al金属残留时,陶瓷/合金界面处析出Ti5Si3相。

Aimed at the effect rules of several typical metal ions from reclaimed shells on contaminating casting surface, with the method of adding metallic elements such as Al, Nb and Mn to shell materials used to actually cast ZTC4 alloy （Ti-6Al-4V） , this study analyzed the influence of different residual metals in casting process on casting surface quality, ceramic/titanium alloy interaction compositions, microstructure morphology and micro-hardness, and discussed the impact of residual casting metal in recycled mould materials on the in- terface stability between ceramic mould and new titanium alloy cast. The results show that the cast surface of ZTC4 alloy using moulds containing Al, Nb or Mn ions looks smooth with no obvious casting defects; com- pared with none metal containing mould, the roughness of ZTC4 cast using shells with residual metal increases markedly ; Al vestigital had little effect on the interface inertness of ceramic against molten titanium alloy, while Nb and Mn can obviously reduce the interface inertness, and to some degree, casting surface roughness can re- flect the interface stability; when the mould contains Al, TisSi3 phase is found at ceramic/metal interface.