The Research of Reinforced Cu-SiCp/ZA40 and Cu-SiCp/AZ91D Metal Matrix Composites' Mechanisms

4th Annual International Workshop on Materials Science and Engineering

Yu, Ting^1 ; Geng, Guihong^1 ; Xue, Penghao^1 ; Zhang, Lei^1

North Minzu University, Yinchuan

750021, China^1

关键词: Al phase;    AZ91D alloy;    Cu layers;    Dispersion strengthening;    Mg17Al12 phase;    Solid solution strengthening;    Strengthening mechanisms;   

Others  :  https://iopscience.iop.org/article/10.1088/1757-899X/381/1/012173/pdf
DOI  :  10.1088/1757-899X/381/1/012173

来源: IOP

【 摘 要 】

In this paper, the strengthening mechanism of the SiCp on two different kinds of metal matrix composites was studied by adding SiCp with a diameter of 4 micron in AZ91D alloy and ZA40 alloy. The study found that the strengthening mechanism was the dispersion strengthening when 0.5-1.5%Wt SiCp was added into ZA40 zinc alloy. In order to solve the wettability of the ZA40 and the SiCp, Cu layer was coated on the surface of SiCp. When Cu-SiCp was added into the ZA40 alloy, α-Al phase blocked by Cu-SiCp at the stage of solidification and crystallization. Therefore, the α-dendrite in the crystalline tissue was decreased and the grain was refined, and the strength of the alloy was improved significantly. SiCp was added to the AZ91D composite, the strengthening mechanism was solid solution strengthening when the adding amount was less than 10%Wt. The SiCp reacted with β-Mg17Al12, generated new Al4C3 phase and strengthened phase Mg2Si, formed Mg-Al solid solution. The formation of Al4C3 played a key role in grain refined and the formation of Mg2Si replaced the harmful divorced eutectic β-Mg17Al12 phase in the material that improved the strength and hardness of the alloy. When SiCp adding amount was more than 10%Wt, in order to alleviate the agglomeration and the wettability of the SiCp and the liquid AZ91D, a Cu layer was coated on SiCp surface, the strengthening mechanisms were both solid solution strengthening and dispersion strengthening.