硬型铸造Ti-Al合金的组织与拉伸性能

Microstructures and Tensile Properties of Ti-Al Based Alloys by Permanent Mold Casting

试验研究了石墨和铸钢两种硬型铸造Ti-Al合金板片状试样的缺陷、层片间距和室温拉伸性能,并与用陶瓷型壳铸造的Ti-Al合金进行对比。结果表明,采用硬型铸造Ti-Al合金在比较高的冷却速度下凝固的板片状试样无宏观和微观裂纹;与陶瓷型壳铸造的组织相比,硬型铸造Ti-Al合金的板片状试样铸态组织平均层片间距大幅度减小,其中石墨型铸造的减小了近一半;由于硬型铸造Ti-Al合金的板片状试样的层片间距的减小使得其室温拉伸强度有较大幅度的提高,其中石墨型铸造板片试样的层片问距减小了0.35μm,屈服强度提高了40 MPa。

The properties the casting plate were studied in this paper,such as,the casting defect,lamellar spacing and room temperature tensile properties of Ti-Al based plate by graphite mold and cast-steel mold,and were compared with the Ti-Al based plate by ceramics mold.The experimental results show that there was no macro and micro crack in these permanent mold casting plates at the higher cooling rate during the solidification;the lamellar spacing of permanent mold casting plate was greatly reduced,compared with that of ceramics mold casting plate,and the lamellar spacing of the graphite mold casting plate was reduced approximately one half;the lamellar spacing was decreased so that the tensile properties clearly increased,for example,the lamellar spacing of the graphite mold casting plate was reduced 0.35 μm,but the yield strength was increased 40 MPa.