铝基复合材料用Al-12Si-xTi系三元活性钎料的制备

摘要

To improve the wettability of Al metal matrix composites (Al-MMCs) by common filler metals,Al-12Si-xTi (x=0.1,0.5,1,3.0; mass fraction,％) system active ternary filler metals were prepared.It was demonstrated that although the added Ti existed within Ti(Al1-xSix)3 (0≤x≤0.15) phase,the shear strength and shear fracture surface of the developed Al-12Si-xTi brazes were quite similar to those of traditional Al-12Si braze due to the presence of similar microstructure of Al-Si eutectic microstructure with large volume fraction.So,small Ti addition (～1％) did not make the active brazes brittle and hard compared with the conventional Al-12Si braze.The measured melting range of each Al-12Si-xTi foil was very similar,i.e.,580-590 ℃,because the composition was close to that of eutectic.For wettability improvement,with increasing Ti content,the interfacial gap between the Al2O3 reinforcement and filler metal (R/M) could be eliminated,and the amount of the remainder of the active fillers on the composite substrate decreased after sessile drop test at 610 ℃ for 30 min.So,the wettability improvement became easy to observe repeatedly with increasing Ti content.Additionally,the amount and size of Ti(AlSi)3 phase were sensitive to the Ti content (before brazing) and Si content (after brazing).%为了改善常用钎料对铝基复合材料的润湿性,制备了新型Al- 12Si-xTi系三元活性钎科.研究表明,所添加的Ti以Ti(Al1-xSix)3(0≤x≤0.15)相存在,但由于钎料的主要组织均为Al-Si共晶组织,所以Al-12Si-xTi钎料与传统Al-12Si钎料具有相似的剪切强度和剪切断口.因此,加入少量Ti(～1％)不会使钎料脆化和硬化；而且Al-12Si-xTi钎料带的成分接近共晶成分,所以熔化区间非常相似,为580～590℃.对于润湿性的改善,是由于随着钎料中Ti含量的增加,Al2O3增强相和钎料金属间的(R/M)界面间隙得到消除的原因.润湿实验后在铝基复合材料表面残留的钎料量也随着钎料含Ti量的增加而减少.因此,Ti对于润湿性的改善可以随着钎料含Ti量的增加而较为容易地被重复观察到.此外,Ti(AlSi)3的量和尺寸对含Ti量(焊接前)和含Si量(焊接后)敏感.