铝合金叶轮线性缺陷的分析

本文分析了航空发动机用铝合金叶轮在加工后荧光检测发现的线性缺陷.结果表明,这种加工后出现的线性缺陷并非裂纹,而是卷入铸件的氧化膜受外力作用后在叶片表面的显现.同时,分析认为这种氧化膜的形成与金属炉料、铸造辅料的洁净度不够以及熔炼、浇注不合理有关.在此基础上,本文提出了采用高纯度、高洁净度的金属炉料和铸造辅料,合理熔炼,充分精炼,设计合理的浇注系统和浇注参数等措施可以预防该类缺陷.

Analysis of Linear Defect of Aluminum Alloy Impeller

The linear defect of an aluminum alloy aero-engine impeller detected through fluorescent penetrating inspection appeared after machining was analyzed in this paper.It was indicated that the linear defect appeared after machining is not crack,it is the appearance of oxide film involved in the casting under the effect of external force.The low purity of furnace charge and accessories and the improper smelting and pouring crafts were regarded as the formation reason of the oxide film.Then the precautionary measures were discussed in this paper. Pure furnace charge and accessories, sound smelting and well refining, and sound designation of gating system can prevent the formation of the oxide film.