摘要
To improve the wettability of common fiUer metals on Al metal matrix composites （ AI-MMCs ） , three kinds of active ternary filler metals, Al-Si-Ti, Zn-Al-Ti and Cu-Al-Ti systems, were prepared by the addition of Ti. Excessive melting temperature made the gravity segregation of Ti remarkable in ingot. The effect of Ti content on the melting point for AI-Si-Ti ternary system was not as sensitive as that for Al-Ti binary system. The Al-12Si-1Ti filler metal showed good ability to form brazing foil during rapid cooling, ductile fracture surface and similar shear strength to conventional Al-12Si filler metal. Moreover, the Al2 03 reinforcements on initial surface could be covered by the Al-12Si-1Ti filler metal without interfacial gaps after sessile drop test. For Zn-9.5Al-0. 5 Ti braze alloy, severe vaporization of Zn and severe segregation of Ti Occurred. During wettability test for traditional Al-12Si and Zn-9.5Al-0. 5Ti, although some Si or Zn could penetrate into the composite, interfacial gap still remained. The prepared Cu-19Al-1 Ti interlayer consisted of primary phase of Al4Cu9 and network Cu-Al-Ti ternary intermetaUic compound, showing poor ability to form foil and very brittle nature. These results demonstrated that Al-Si-Ti system should be promising for Al-MMCs.
To improve the wettability of common fiUer metals on Al metal matrix composites （ AI-MMCs ） , three kinds of active ternary filler metals, Al-Si-Ti, Zn-Al-Ti and Cu-Al-Ti systems, were prepared by the addition of Ti. Excessive melting temperature made the gravity segregation of Ti remarkable in ingot. The effect of Ti content on the melting point for AI-Si-Ti ternary system was not as sensitive as that for Al-Ti binary system. The Al-12Si-1Ti filler metal showed good ability to form brazing foil during rapid cooling, ductile fracture surface and similar shear strength to conventional Al-12Si filler metal. Moreover, the Al2 03 reinforcements on initial surface could be covered by the Al-12Si-1Ti filler metal without interfacial gaps after sessile drop test. For Zn-9.5Al-0. 5 Ti braze alloy, severe vaporization of Zn and severe segregation of Ti Occurred. During wettability test for traditional Al-12Si and Zn-9.5Al-0. 5Ti, although some Si or Zn could penetrate into the composite, interfacial gap still remained. The prepared Cu-19Al-1 Ti interlayer consisted of primary phase of Al4Cu9 and network Cu-Al-Ti ternary intermetaUic compound, showing poor ability to form foil and very brittle nature. These results demonstrated that Al-Si-Ti system should be promising for Al-MMCs.
基金
The present research was sponsored by the National Natural Science Foundation of China （ No. 50875199）, and by State Key Laboratory of Advanced Welding Production Technology, Harbin Institute of Technology, China.
