【摘要】 研究了热处理对大尺寸铸态高Nb-TiAl基合金组织中β相偏析的影响。实验结果表明,通过在α+γ两相区保温适当时间可以消除合金组织中的β相偏析。合金试样经1250℃/24h+900℃/30min/AC热处理后,可以有效消除晶界处的β-偏析和片层内的α-偏析;而经1280℃/6h+900℃/30min/AC就可以达到1250℃保温24h的效果,保温12h后β相完全被消除,但片层团平均晶粒尺寸有所长大,从原来的75μm增长到123μm左右。更多还原

【Abstract】 The effect of the heat treatment on the elimination of the β phase segregation in as-cast high Nb containing TiAl alloy on large scale was studied.The results show that the β phase segregation can be eliminated by holding appropriate time in the two phase region of α+γ.The β-segregation at the grain boundaries and α-segregation in lamellar colonies can be efficiently eliminated after 1250℃/24h + 900℃/30min /AC for the alloy samples;but after 1280℃/6h+900℃/30min/AC,the volume fraction of β phase is very small and completely eliminated after holding 12h at the cost of the average lamellar colony size coarse from 75μm to 123μm.更多还原