(西安交通大學(xué) 機(jī)械工程學(xué)院， 西安 710049)
摘 要: 研究了激光功率、掃描速度對原位合成TiCp/Al表層復(fù)合材料與基底的界面結(jié)合和熔覆層組織均勻性的影響。通過調(diào)整工藝參數(shù)，獲得了有良好冶金結(jié)合的界面和TiC顆粒分布均勻的熔覆組織。結(jié)果表明：在激光功率一定時，過低的掃描速度將使激光束前端一定距離內(nèi)的基底材料在表面熔化前被加熱時間太長，以致表面氧化；而過高的掃描速度會使靠近界面處的粉料中合成反應(yīng)不能充分完成而殘留一些粉末；這兩種情況都影響了熔覆層和基底的結(jié)合。隨著激光輸入比能的降低，熔覆組織的均勻性降低，這是由于合成反應(yīng)未充分完成所致。當(dāng)激光功率為2200～2500W，掃描速度為7～10mm/s時，在ZL104合金表面可獲得組織均勻、界面結(jié)合良好的TiCp/Al復(fù)合材料熔覆層。
關(guān)鍵字: 激光熔覆； 原位合成； TiCp/Al基復(fù)合材料；界面結(jié)合； 組織均勻性
bonding and structure uniformity of in-situ synthesis
TiCp/Al composites in laser cladding process
（School of Mechanical Engineering， Xi'an Jiaotong University，
Xi′an 710049， P.R.China）
Abstract:The influence of laser power and scanning velocity on interface bonding between clad layer and substrate and uniformity of microstructure in composite surface layer was studied. By means of adjusting these parameters，the excellent interface bonding and uniform microstructure can be obtained. The experiment results show that when the laser power is in a certain value，the lower scanning velocity leads the surface of substrate ahead of laser beam to maintain a longer time at high temperature，so that an oxide film is formed. But，if the scanning velocity is too fast，the synthetic reaction in powder materials near the substrate will be not enough. Either of these two situations will deteriorate the interface bonding. The experiment results also show that the lower the laser input specific energy is，the worse the uniformity of microstructure will be. This phenomenon is caused by insufficient synthetic reaction in powder materials. When the laser power is 2200～2500W，the scanning velocity is 7～10mm/s, an excellent TiCp/Al composite surface layer can be obtained on ZL104Alalloy.
Key words: laser cladding; in-situ synthesis; TiCp/Al composite; interface bonding; uniformity of microstructure
