Journal of Inorganic Materials ›› 2016, Vol. 31 ›› Issue (6): 602-606.DOI: 10.15541/jim20150497

• Orginal Article • Previous Articles     Next Articles

Direct Brazing of Al/Al2O3 without Wettability of Molten Metal

CHEN Fan1, SHI Kai-Cheng1, SUN Shi-Yang1,2, ZHAO Bo-Wen1, SHANG Hai-Long1, LI Ge-Yang1   

  1. (1. The State Key Laboratory of Metal Matrix Composites, Shanghai Jiaotong University, Shanghai 200240, China; 2. College of Mechanical Engineering, Inner Mongolia University of Science and Technology, Baotou 014010, China)
  • Received:2015-10-13 Revised:2015-12-25 Published:2016-06-20 Online:2016-05-19
  • About author:CHEN Fan. E-mail:
  • Supported by:
    National Natural Science Foundation of China(51371118, 51401120)


Al2O3 cannot be directly brazed with aluminum due to the poor wettability of aluminum on alumina below 850℃. Based upon effect of sputtered aluminum wetting on Al2O3, a direct brazing method was proposed to utilize sputtered Al-based films as brazing fillers on alumina. The results show that direct brazing of Al2O3 by Al and Al-Cu alloy can be achieved at 680℃ in vacuum with vacuum level only of 0.1 Pa. Through this method, the shear strength of joint with pure Al as brazing filler is 115 MPa and that with Al-1.6at% Cu is up to 163 MPa. When the Cu content in the Al-Cu alloy increases to 14.3at%, the shear strength of joint decreases to 127 MPa, due to the joint fracture generating at the interface caused by the interfacial segregation of Cu. Moreover, the principle of this direct brazing method not based on wettability of molten metal is analyzed.

Key words: brazing, wettability, alumina, joint strength, aluminum alloy

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