论文部分内容阅读
Beta-solidifying TiAl alloy has great potential in the field of aero-industry as a cast alloy.In the present work,the influence of cooling rate during mushy zone on solidification behavior of Ti-44Al-4Nb-2Cr-0.1B alloy was investigated.A vacuum induction heating device combining with temperature control system was used.The Ti-44Al-4Nb-2Cr-0.1B alloy solidified from superheated was melted to β phase with the cooling rates of 10,50,100,200,400 and 700 K·min~(-1),respectively.Results show that with the increase in cooling rate from 10 to 700 K·min~(-1),the colony size of α_2/γ lamella decreases from 1513 to48 urn and the solidification segregation significantly decreases.Also the content of residual B2 phase within α_2/γlamellar colony decreases with the increase in cooling rate.In addition,the alloy in local interdendritic regions would solidify in a hypo-peritectic way,which can be attributed to the solute redistribution and enrichment of Al element in solidification.
Beta-solidifying TiAl alloy has great potential in the field of aero-industry as a cast alloy. In the present work, the influence of cooling rate during mushy zone on solidification behavior of Ti-44Al-4Nb-2Cr-0.1B alloy was investigated . A vacuum induction heating device combining with temperature control system was used. The Ti-44Al-4Nb-2Cr-0.1B alloy solidified from superheated was melted to β phase with the cooling rates of 10, 50, 100, 200, 400 and 700 K · min ~ 1), respectively. Results show that with the increase in cooling rate from 10 to 700 K · min ~ (-1), the colony size of α_2 / γ lamella decreases from 1513 to 48 urn and the solidification segregation significantly decreases.Also the content of residual B2 phase within α_2 / γlamellar colony decreases with the increase in cooling rate. In addition, the alloy in local interdendritic regions would solidify in a hypo-peritectic way, which can be attributed to the solute redistribution and enrichment of Al element in solidification .