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采用无B的含Hf镍基合金作为中间层合金,分别对含Re的第二代镍基单晶高温合金(CMSX-4,铸态)和第三代镍基单晶高温合金(SXG3,完全热处理态)进行过渡液相(TLP)连接,并分析了连接区的显微组织演变以及降熔元素分布,测试了连接区的显微硬度.结果表明,在1290℃真空保温24 h后,CMSX-4和SXG3合金的TLP连接均已完成,2种合金的TLP连接过程也均符合经典模型.以含Hf的镍基合金作为中间层合金时,在连接区内没有出现扩散影响区.CMSX-4合金的固溶处理可在TLP连接过程中同步完成,缩短了热处理工艺.SXG3合金中的C与Hf结合在液相中形成固相Hf C,降低熔体中Hf浓度,缩短了等温凝固阶段的时间.研究表明,通过含Hf的TLP连接可以研究小角度晶界的界面稳定性,其中在1150℃保温热处理后,SXG3合金小角度晶界出现不连续脱溶转变的临界区间在10°~17°之间.
The non-B containing Hf nickel-base alloy was used as the intermediate layer alloy. The effects of ReX on the second generation nickel base single crystal superalloy (CMSX-4, as-cast) and third generation nickel base single crystal superalloy (SXG3, (TLP), and the evolution of micro-structure and the distribution of melting elements in the connection zone were analyzed.The microhardness of the connection zone was tested.The results showed that after the vacuum insulation at 1290 ℃ for 24 h, CMSX -4 and SXG3 alloy TLP connections have been completed, the TLP connection process of the two alloys are also in line with the classical model.With the Hf-containing nickel-based alloy as the middle layer alloy, there is no diffusion effect zone in the connection area.CMSX- 4 alloy solution treatment can be completed simultaneously in the TLP connection process, shortening the heat treatment process.SXG3 alloy C and Hf in the liquid phase to form a solid phase Hf C, reducing the melt Hf concentration, shortening the isothermal coagulation stage .The results show that the interfacial stability at low angle grain boundaries can be studied by the TLP connection with Hf. After the heat treatment at 1150 ℃, the critical range of discontinuous solution transformation occurs at the small angle grain boundaries of SXG3 alloy at 10 ° ~ 17 ° between.