一、前言 显微孔穴,即显微疏松是铸件中常见的,严重危害铸件性能的主要缺陷之一。特别是那些结晶间隔宽的合金形成显微孔穴的倾向性尤为严重。据报导,在法国的发动机生产厂中,因显微孔穴超差而报废的铸造涡轮叶片往往要占报废的铸造涡轮叶片总数的90％。 First, the foreword Micro-hole, that is, loose microspheres is common in castings, one of the major defects that seriously endanger the performance of castings. In particular, the tendency of the wide-spacing alloys to form micro-cavities is particularly serious. It has been reported that foundry turbine blades that have been scrapped due to microscopic hole overhangs often account for up to 90% of the total number of scrap foundry turbine blades in an engine plant in France.