Journal of South China University of Technology (Natural Science Edition) ›› 2018, Vol. 46 ›› Issue (10): 117-125.doi: 10.3969/j.issn.1000-565X.2018.10.016

• Mechanical Engineering • Previous Articles     Next Articles

Microstructures and Mechanical Properties of AlSi10Mg Aluminum Alloy Fabricated by Laser Melting Deposition

 Lǚ Fei1 TIAN Zongjun1 LIANG Huixin1 XIE Deqiao1 SHEN Lida1 XIAO Meng2    

  1. 1． College of Mechanical and Electrical Engineering，Nanjing University of Aeronautics and Astronautics，Nanjing 210016， Jiangsu，China; 2． Nanjing Institute of Advanced Laser Technology，Nanjing 210038，Jiangsu，China
  • Received:2018-03-21 Revised:2018-06-14 Online:2018-10-25 Published:2018-09-01
  • Contact: 吕非( 1994-) ，男，博士生，主要从事增材制造方面的研究． E-mail: lvfei@nuaa.edu.cn
  • About author:吕非( 1994-) ，男，博士生，主要从事增材制造方面的研究
  • Supported by:
      the Young Scientists Fund of the National Natural Science Foundation of China( 51605473) ， the Science and Technology Support Program of Jiangsu( BE2014009-1) ， the Key Ｒesearch and Development Program of Jiangsu ( BE2015161， BE2016010-3) ， the Science and Technology Planning Project of Jiangsu Province， China( BE2015029) and the Natural Science Foundation of Jiangsu Province( BK20161476) 

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Abstract: In order to improve the manufacturing quality of the AlSi10Mg aluminum alloy fabricated by Laser Melting Deposition based on coaxial powder feeding, this paper carried out the single tracks test, block samples forming experiments and tensile property test to investigate the variation trend on the microstructure and property under different process parameters. The experimental results showed that the manufacturing quality of the LMD processed samples was significantly governed by energy density of laser beam and the hatch spacing. tensile property was improved by decreasing the level of porosity and enhancing the effect of solid solution strengthening. After process optimization, the morphology of the single tracks was smooth without spheroidization. The relative density of the block samples was increased to 99.2% without larger pores and cracks. The microstructure of samples had directional rapid solidification characteristics with Al-Si eutectic microstructure contained three microstructures of cellular crystal, columnar dendritic crystal and divergent dendrite crystal. With the increase of cooling rate, the solubility of Si phase in Al matrix was increased to 7.6%. The effect of solid solution strengthening was enhanced. Therefore, AlSi10Mg samples fabricated by laser melting deposition with good performance could be obtained by optimizing the process parameters. The tensile stress of the samples was 292MPa, which was 33% higher than that of the cast samples.

Key words:  laser melting deposition ( LMD) , AlSi10Mg, microstructure, micro-hardness, tensile property

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