Microstructure, solidification behavior and mechanical properties of Al-Si-Mg-Ti/TiC fabricated by selective laser melting

被引：77

作者：

Li, Xinwei ^{[1
,2
]}

Shi, Shi ^{[3
]}

Han, Shuang ^{[1
,2
]}

Hu, Xiaogang ^{[1
,2
]}

Zhu, Qiang ^{[1
,2
]}

Lu, Hongxing ^{[1
]}

Li, Wenwu ^{[4
]}

Shi, Yusheng ^{[4
]}

Ding, Hui ^{[5
]}

机构：

[1] Southern Univ Sci & Technol, Shenzhen Key Lab Addit Mfg High Performance Mat, Shenzhen 518055, Peoples R China

[2] Southern Univ Sci & Technol, Dept Mech & Energy Engn, Shenzhen 518055, Peoples R China

[3] Shenzhen Univ, Guangdong Prov Key Lab Durabil Marine Civil Engn, Coll Civil & Transportat Engn, Shenzhen Durabil Ctr Civil Engn, Shenzhen 518060, Guangdong, Peoples R China

[4] Huazhong Univ Sci & Technol, Sch Mat Sci & Engn, State Key Lab Mat Proc & Die & Mould Technol, Wuhan 430074, Peoples R China

[5] Southeast Univ, Sch Mat Sci & Engn, Nanjing 211189, Peoples R China

来源：

ADDITIVE MANUFACTURING | 2020年 / 34卷

基金：

中国国家自然科学基金; 中国博士后科学基金;

关键词：

Powder bed fusion; Selective laser melting; Al-Si-Mg-Ti/TiC; Microstructure; Mechanical properties;

D O I：

10.1016/j.addma.2020.101326

中图分类号：

T [工业技术];

学科分类号：

08 ;

摘要：

Ball-milled Ti/TiC composite particles (TiC nanoparticles assembled on Ti microparticles) were designed, prepared, and mixed with Al-Si-Mg powder to fabricate an Al-Si-Mg-Ti alloy with TiC nanoparticles (Al-Si-Mg-Ti/TiC) by selective laser melting (SLM). Microstructure features, solidification behavior, and mechanical properties were investigated, and the relationship among them was established. The SLM-manufactured Al-Si-Mg-Ti/TiC material exhibited fine equiaxed-shaped alpha(Al) grains with nanoscale Si4Ti5 phases and Mg segregation along the grain boundaries. This structure benefited from heterogeneous nucleation as well as the grain growth restriction capabilities of TiC nanoparticles on alpha(Al), fast diffusion of Ti in the superheated Al liquid, and high chemical activity of Ti to Si during solidification. Furthermore, Ti enrichment in some local areas of the high-temperature pool and the consequently intense Marangoni convection improved the wettability between TiC nanoparticles and liquid Al without the interfacial reaction. Consequently, the SLM-manufactured Al-Si-Mg-Ti/TiC showed a high ultimate tensile strength of up to 562 +/- 7 MPa and an elongation of up to 8.8 % +/- 1.3 % before fracture. These increased mechanical properties are attributed to the combined effect of grain refinement and Orowan and load-bearing strengthening mechanisms.

引用

页数：9

共 29 条

[1] On the Breakdown of SiC during the Selective Laser Melting of Aluminum Matrix Composites [J].