A Comparative Characterization of the Microstructures and Tensile Properties of As-Cast and Thixoforged in situ AM60B-10 vol% Mg2Sip Composite and Thixoforged AM60B

Metals

Suqing Zhang²  Tijun Chen¹  Faliang Cheng²  Pubo Li² 

[1]Key Laboratory of Advanced Processing and Recycling of Nonferrous Metals, Lanzhou University of Technology, Lanzhou 730050, China

关键词: thixoforged;    in situ Mg₂Si_p/AM60B composite;    tensile properties;   

DOI  :  10.3390/met5010457

来源: mdpi

【 摘 要 】

The microstructure and tensile properties of the thixoforged in situ Mg₂Si_p/AM60B composite were characterized in comparison with the as-cast composite and thixoforged AM60B. The results indicate that the morphology of α-Mg phases, the distribution and amount of β phases and the distribution and morphology of Mg₂Si particles in thixoforged composite are completely different from those in as-cast composite. The Mg₂Si particles block heat transfer and prevent the α-Mg particles from rotation or migration during reheating. Both the thixoforged composite and thixoforged AM60B alloy exhibit virtually no porosity in the microstructure. The thixoforged composite has the highest comprehensive tensile properties (ultimate tensile strength (UTS)) of 209 MPa and an elongation of 10.2%. The strengthening mechanism of the Mg₂Si particle is the additive or synergetic effect of combining the load transfer mechanism, the Orowan looping mechanism and the dislocation strengthening mechanism. Among them, the load transfer mechanism is the main mechanism, and the latter two are minor. The particle splitting and interfacial debonding are the main damage patterns of the composite.

【 授权许可】

CC BY   
© 2015 by the authors; licensee MDPI, Basel, Switzerland.