title: Phase-Transformation-Induced Extra Thermal Expansion Behavior of (SrxBa1-x)TiO3/Cu Composite.
abstract: The properties of metal matrix composites (MMCs) can be optimized effectively through adjusting the type or the volume fraction of reinforcement. Generally, the coefficient of thermal expansion (CTE) of MMCs can be reduced by increasing the volume fraction of the reinforcement with lower CTE than metal matrix. However, it is great challenge to fabricate low CTE MMCs with low reinforcement volume fraction because of the limitation of reinforcement CTEs. SrxBa1-xTiO3 (SBT) powder presents negative thermal expansion behavior during the phase transformation from tetragonal to cubic phase. Here, we demonstrate that the phase transformation of SBT can be utilized to reduce and design the thermal expansion properties of SBT particle-reinforced Cu (SBT/Cu) composite, and ultralow CTE can be obtained in SBT/Cu composite. The X-ray diffraction analysis on heating indicates that the temperature range of phase transformation is extended greatly, therefore, the low CTE can be achieved within wide temperature range. Landau-Devonshire theory study on the phase transformation behaviors of SBT particles in the composite indicates that thermal mismatch stress significantly affects the Curie temperature of SBT particles and the CTE of the composite. The results given in the present study provide a new approach to design the MMCs with low CTE.
authors.affiliation: State Key Laboratory for Advanced Welding and Joining, Harbin Institute of Technology, Harbin 150001 P.R. China.
authors.forename: Jie
authors.initials: J
authors.lastname: Sheng
authors.affiliation: State Key Laboratory for Advanced Welding and Joining, Harbin Institute of Technology, Harbin 150001 P.R. China.
authors.forename: Lidong
authors.initials: L
authors.lastname: Wang
authors.affiliation: Department of Materials Science and Engineering, Shenzhen Graduated School, Harbin Institute of Technology, Shenzhen 518055, P.R. China.
authors.forename: Shouwei
authors.initials: S
authors.lastname: Li
authors.affiliation: Department of Materials Science and Engineering, Shenzhen Graduated School, Harbin Institute of Technology, Shenzhen 518055, P.R. China.
authors.forename: Benke
authors.initials: B
authors.lastname: Yin
authors.affiliation: Department of Materials Science and Engineering, Shenzhen Graduated School, Harbin Institute of Technology, Shenzhen 518055, P.R. China.
authors.forename: Xiangli
authors.initials: X
authors.lastname: Liu
authors.affiliation: State Key Laboratory for Advanced Welding and Joining, Harbin Institute of Technology, Harbin 150001 P.R. China.
authors.forename: Wei-Dong
authors.initials: WD
authors.lastname: Fei