原位反应TiC颗粒对喷射沉积Al-20Si-5Fe合金微观组织的影响

Effect of in situ TiC Particulate on the Microstructure of Spray Deposited Al-20Si-5Fe Alloy

利用熔铸－原位反应喷射沉积成形技术制备了ＴｉＣ颗粒增强Ａ１－２０Ｓｉ－ＳＦｅ复合材料．分析了内生ＴｉＣ颗粒对喷射沉积Ａｌ－２０Ｓｉ－５Ｆｅ合金微观组织的影响．结果表明：喷射沉积Ａ１－２０ＳＩ－５Ｆｅ合金微观组织中常出现脆性、针状的 Ａ１－ＳＩ－Ｆｅ三元金属间化合物相．在 Ａ１－２０Ｓｉ－５Ｆｅ合金中内生一定量的 ＴｉＣ颗粒，有助于减小粗晶Ｓｉ颗粒的尺寸、消除针状的 Ａ１－Ｓｉ－－Ｆｅ三元金属间化合物相．

A TiC/A1-20Si-5Fe composite is fabricated by melt in situ reaction spray forming and effect of in situ TiC particulate on the microstructure of spray-deposited Al-20Si-5Fe alloy is studied. Both theoretical and experimental results have shown that some Al-Si-Fe intermetallic phases with needle-like structure exist in the spray-deposited Al-20Si-5Fe alloy, which is harmful to the tensile properties of the composites. The needle- like intermetallic phases can be entirely absent in the final product after 5%Tic (mass fraction) particulates are in situ formed in spray-deposited Al-20Si-5Fe alloy.