The room temperature compressive plasticity of Fe75MosP10Cs.3B1.7 bulk metallic glass (BMG) was improved from 0.5% to 1.8% by increasing the sample diameter from 1.5 mm to 2.0 mm. With increasing the sample diameter...The room temperature compressive plasticity of Fe75MosP10Cs.3B1.7 bulk metallic glass (BMG) was improved from 0.5% to 1.8% by increasing the sample diameter from 1.5 mm to 2.0 mm. With increasing the sample diameter to 2.0 mm, a heterogeneous microstructure with in-situ formed a-Fe dendrite sparsely distributed in the amorphous matrix can be attained. This heterogeneous mierostructure is conceived to be highly responsible for the enhanced global plasticity in this marginal Fe-based BMG.展开更多
To develop new type of high damping metal matrix composites, large grain size barium titanate (BaTiO3) ceramic was sintered and added into Al powder to fabricate BaTiO3/Al composites through the powder metallurgy me...To develop new type of high damping metal matrix composites, large grain size barium titanate (BaTiO3) ceramic was sintered and added into Al powder to fabricate BaTiO3/Al composites through the powder metallurgy method and hot extrusion. The damping properties of BaTiO3 ceramic, Al matrix and BaTiO3/Al composites were examined by dynamic mechanical analysis in the temperature range from 273 K to 573 K. The results show that although BaTiO3 exhibits high damping (tan δ=0.12) below 400 K, the damping capacity of 10%BaTiO3/Al (mass fraction) composites below 400 K is not increased as compared to the Al matrix. On the other hand, the damping capacity above 450 K is greatly enhanced due to the motion of dislocations at the interfaces between ceramic particles and Al matrix. The failure of exerting the intrinsic damping of BaTiO3 particles in the composites is attributed to the poor interface bonding between the particles and the matrix. The tensile strength of the composite is 42% higher than that of the Al matrix, which indicates the possibility of obtaining high strength and high damping composites via interface improvement and the addition of high volume fraction of large grain BaTiO3 particles.展开更多
基金Foundation item: Project (SWU110046) supported by the Startup Foundation for Doctors of Southwest University, ChinaProjects (XDJK2012C017,CDJXS11132228, CDJZR10130012) supported by the Fundamental Research Funds for the Central Universities, China+1 种基金Project (CSTS2006AA4012) supported by the Chongqing Science and Technology Commission, ChinaProject (T201112) supported by Shenzhen Key Laboratory of Special Functional Materials,Shenzhen University,China
文摘The room temperature compressive plasticity of Fe75MosP10Cs.3B1.7 bulk metallic glass (BMG) was improved from 0.5% to 1.8% by increasing the sample diameter from 1.5 mm to 2.0 mm. With increasing the sample diameter to 2.0 mm, a heterogeneous microstructure with in-situ formed a-Fe dendrite sparsely distributed in the amorphous matrix can be attained. This heterogeneous mierostructure is conceived to be highly responsible for the enhanced global plasticity in this marginal Fe-based BMG.
基金Project (51001071) supported by the National Natural Science Foundation of China Projects (2012CB619400, 2012CB619600) supported by the National Basic Research Program of China+1 种基金Project (2010DFA52550) supported by the International S&T Cooperation Program of ChinaProject (20100470031) supported by China Postdoctoral Science Foundation
文摘To develop new type of high damping metal matrix composites, large grain size barium titanate (BaTiO3) ceramic was sintered and added into Al powder to fabricate BaTiO3/Al composites through the powder metallurgy method and hot extrusion. The damping properties of BaTiO3 ceramic, Al matrix and BaTiO3/Al composites were examined by dynamic mechanical analysis in the temperature range from 273 K to 573 K. The results show that although BaTiO3 exhibits high damping (tan δ=0.12) below 400 K, the damping capacity of 10%BaTiO3/Al (mass fraction) composites below 400 K is not increased as compared to the Al matrix. On the other hand, the damping capacity above 450 K is greatly enhanced due to the motion of dislocations at the interfaces between ceramic particles and Al matrix. The failure of exerting the intrinsic damping of BaTiO3 particles in the composites is attributed to the poor interface bonding between the particles and the matrix. The tensile strength of the composite is 42% higher than that of the Al matrix, which indicates the possibility of obtaining high strength and high damping composites via interface improvement and the addition of high volume fraction of large grain BaTiO3 particles.