活性钎料钎接Si_3N_4陶瓷的机理研究

通过钎料中常用活性材料与被钎陶瓷Ｓｉ＿３Ｎ＿４之间的物理现象和化学反应，讨论了活性材料所起的作用，即通过活性金属与Ｓｉ＿３Ｎ＿４陶瓷的化学反应形成反应过渡层而结合，同时活性材料改善了钎料在Ｓｉ＿３Ｎ＿４陶瓷表面的漫流性能．但因为反应产物与Ｓｉ＿３Ｎ＿４陶瓷热物理性能相差较大，故活性材料的加入量应限制在一定范围以内。用Ａｇ－Ｃｕ－Ｔｉ钎料钎接Ｓｉ＿３Ｎ＿４／钢时，在Ｓｉ＿３Ｎ＿４／钎料过渡区生成了富ＴｉＮ层和富Ｔｉ＿３Ｓｉ＿５层，控制这两个反应结合层的成分和厚度可能是提高钎接接头强度的关键之一。此外在一定范围内增加钎料层厚度时，钎接接头强度有明显提高。

Investigation of Brazing Mechamism of Ceramics Si_3N_4 with Activated Filler Metal

From the amalysis of both physical phenomenon and the chemical reaction be-tween the activated material occured with the commonlv used filler metal and Si_3N_4,the rolesplayed by the activated material are investigated.It is found that the activated elements reactwith Si_3N_4 to form a transition bonding layer.Also,the activated elements improve greatlythe spreading ability of the filler metal over the Si_3N_4 surface.However duo to the great dif-ference of the thermophysical property between reacting products.and Si_3N_4 the quantity ofactivated material added into the filler metal must be controled within certain limits.TheTiN-rich laver and the Ti_3N_4-rich layer are formed at the interface between Si_3N_4 and thefiller metal as the Si_3N_4/steel with the Ag-Cu-Ti filler metal are brazed togather controllingthe thickness of the two layers might be one of the key factors for increasing the jointstrength.The experiment has indicated the obvious increas in joint strength with the increase in thickness of filler metal laver within certain limits.