Effect of Brazing Conditions on Microstructure and Mechanical Properties of Al2O3/Ti—6Al—4V Alloy Joints Reinforced by TiB Whiskers
来源期刊：JOURNAL OF MATERIALS SCIENCE TECHNOLOG2013年第10期
论文作者：Minxuan Yang Peng He Tiesong Lin
文章页码：961 - 970
摘 要：Al2O3and Tie6Ale4V alloy were brazed with AgeCueTi+B fillers in different brazing conditions.Effects of brazing temperature,holding time and additive Ti content on joints microstructure and shear strength were investigated by scanning electron microscopy,energy dispersive spectrometry,X-ray diffraction,transmission electron microscopy and shear testing.Results indicate that TiCu and Ti（Cu,Al） decrease,but Ti2Cu and Ti2（Cu,Al） increase in brazing seam with increasing brazing temperature,holding time and additive Ti content.Area consisting of Ti3（Cu,Al）3O and TiO near Al2O3becomes gradually discontinuous from continuity when brazing temperature rises or holding time extends.As Ti additive content increases,TiO is absent near Al2O3;area consisting of only Ti3（Cu,Al）3O thickens.TiB whiskers are in situ synthesized by Ti and B atoms during brazing process.The brazing temperature,holding time and additive Ti content on joints microstructure influence the joints shear strength directly.The shear strength of joints,obtained at 850℃ holding for10 min,reaches the maximum of 78 MPa.According to the experimental results,phase diagram and thermodynamics calculation,the interface evolution mechanism of the Al2O3/Tie6Ale4V alloy joint was analyzed.
Minxuan Yang1,2，Peng He1，Tiesong Lin1
1. State Key Laboratory of Advanced Welding and Joining,Harbin Institute of Technology2. Beijing Power Machinery Research Institute
摘 要：Al2O3and Tie6Ale4V alloy were brazed with AgeCueTi+B fillers in different brazing conditions.Effects of brazing temperature,holding time and additive Ti content on joints microstructure and shear strength were investigated by scanning electron microscopy,energy dispersive spectrometry,X-ray diffraction,transmission electron microscopy and shear testing.Results indicate that TiCu and Ti（Cu,Al） decrease,but Ti2Cu and Ti2（Cu,Al） increase in brazing seam with increasing brazing temperature,holding time and additive Ti content.Area consisting of Ti3（Cu,Al）3O and TiO near Al2O3becomes gradually discontinuous from continuity when brazing temperature rises or holding time extends.As Ti additive content increases,TiO is absent near Al2O3;area consisting of only Ti3（Cu,Al）3O thickens.TiB whiskers are in situ synthesized by Ti and B atoms during brazing process.The brazing temperature,holding time and additive Ti content on joints microstructure influence the joints shear strength directly.The shear strength of joints,obtained at 850℃ holding for10 min,reaches the maximum of 78 MPa.According to the experimental results,phase diagram and thermodynamics calculation,the interface evolution mechanism of the Al2O3/Tie6Ale4V alloy joint was analyzed.
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