Effects of thermal cycling on thermal expansion behaviors of
b-LiAlSiO4 reinforced copper matrix composites
(1. School of Materials Science and Engineering, Harbin Institute of Technology, Harbin 150001, China;
2. Harbin Dongda High-tech Material Co., Ltd., Harbin 150060, China;
3. School of Mechanical Engineering, Qinghai University, Xi’ning 810016, China)
2. Harbin Dongda High-tech Material Co., Ltd., Harbin 150060, China;
3. School of Mechanical Engineering, Qinghai University, Xi’ning 810016, China)
Abstract: β-LiAlSiO4 reinforced Cu matrix composites (Euc/Cu) were fabricated by hot-pressed sintering process. Thermal expansion behaviors of Euc/Cu composites were studied during the thermal cycling process. Upon twice thermal cycle, the temperature dependence of the coefficients of thermal expansion (CTE) for Euc/Cu composites tends to be stable. The CTEs of the composite can be obviously decreased by the releasing of the thermal mismatch stress (TMS) in thermal cycling process. The TMS induces the irreversible phase transition of Li+ order−disorder of Euc particles in the composite. Meanwhile, the relaxation of TMS during thermal cycling causes the twins deformation of matrix in the Euc/Cu composites.
Key words: copper matrix composite; thermal expansion; residual stress; phase transition