Heat Treatment of Metals ›› 2022, Vol. 47 ›› Issue (9): 65-70.DOI: 10.13251/j.issn.0254-6051.2022.09.012

• PROCESS RESEARCH • Previous Articles     Next Articles

Effect of cryogenic treatment on microstructure and mechanical properties of 15%SiCp/2009 aluminum matrix composite

Pan Ran1, Liu Baosheng1, Zeng Yuansong1, Qu Haitao1, Wang Dong2, Mu Yanhong1   

  1. 1. AVIC Manufacturing Technology Institute, Beijing 100024, China;
    2. Institute of Metal Research, Chinese Academy of Sciences, Shenyang Liaoning 110016, China
  • Received:2022-05-31 Revised:2022-07-10 Published:2022-10-18

Abstract: Effect of long time cryogenic treatment on microstructure and mechanical properties of solution treated and aged SiC particles reinforced aluminum matrix composite was studied by means of hardness tests, X-ray diffraction analysis, mechanical tests and transmission electron microscope (TEM) observation. The mechanism of cryogenic treatment improving mechanical properties of the tested composite was analyzed in terms of microstructure. The results show that the hardness of the aged aluminum matrix composite with cryogenic treatment reaches the peak value (about 211.7 HV0.1) by 2 h earlier than that without cryogenic treatment. During the whole aging stages, the hardness of aged specimens with cryogenic treatment is higher than that without cryogenic treatment. During the under-aging stage, there are fine and uniformly distributed needle-like precipitates in microstructure of the specimens with cryogenic treatment, which is not apparent for that without cryogenic treatment. During the over-aging stage, large-size precipitates appear in both groups of the specimens with and without cryogenic treatment, the precipitate size and distribution are obviously uneven in that without cryogenic treatment, but the mechanical properties of both groups tend to be almost the same with the increase of aging time, as the effect of cryogenic treatment on mechanical properties of aluminum matrix composites is declined.

Key words: particle-reinforced aluminum matrix composite, cryogenic treatment, aging, microstructure

CLC Number: