Acta Metallurgica Sinica (English Letters) ›› 2018, Vol. 31 ›› Issue (6): 641-649.DOI: 10.1007/s40195-017-0689-x

Special Issue: 2018年复合材料专辑

• Orginal Article • Previous Articles     Next Articles

Thermal Properties of Mg-Al/AlN Composites Fabricated by Powder Metallurgy

Jie Chen1(), Chong-Gao Bao2, Zhi-Wei Liu2, Ben-Shuang Sun1(), Yong-Chun Shu1, Qing-Kui Li1   

  1. 1 Henan Province Industrial Technology Research Institute of Resources and Materials, Zhengzhou University,Zhengzhou 450001, China
    2 State Key Laboratory for Mechanical Behavior of Materials,School of Materials Science and Engineering, Xi’an Jiaotong University, Xi’an 710049, China;
  • Received:2017-07-14 Revised:2017-08-15 Online:2018-06-10 Published:2018-05-31

Abstract:

Magnesium matrix composites reinforced with AlN particles were fabricated by the powder metallurgy technique. Different mixing methods were used in this study to control the distribution of AlN particles. The microstructure, thermal diffusivity and thermal expansion of the Mg-Al/AlN composites using different mixing methods were investigated. The results showed that the intergranular and intragranular distributions of AlN particles were obtained, respectively, by controlling the mixing methods. The composite with intragranular particles exhibited lower thermal diffusivity because of the existences of more interfaces, defects and grain boundaries, which acted as scattering centers and reduced the mean free path of electrons and phonons. The existence of AlN particles lowered the coefficient of thermal expansion (CTE) and enhanced the dimensional stability of the composites. And the use of the improved mixing method further reduced the CTE of Mg-Al/AlN composites.

Key words: Magnesium matrix composite, Microstructure, Thermal diffusivity, Thermal expansion, Mixing