TY - JOUR
T1 - Rapid fabrication of Nb-Si based alloy by selective laser melting
T2 - Microstructure, hardness and initial oxidation behavior
AU - Guo, Yueling
AU - Jia, Lina
AU - Sun, Shaobo
AU - Kong, Bin
AU - Liu, Jinhui
AU - Zhang, Hu
N1 - Publisher Copyright:
© 2016
PY - 2016/11/5
Y1 - 2016/11/5
N2 - Nb-18Si-24Ti-2Cr-2Al-2Hf (at%) alloy was fabricated by selective laser melting (SLM). The microstructure, hardness and oxidation behavior of Nb-Si based alloy via SLM were investigated. Results showed that the relative density of SLM alloy under the optimized processing parameters was 98.27%. The as-built alloy consisted of Nb solid solution (Nbss), αNb5Si3, βNb5Si3 and Nb3Si. Sphere shaped Nbss phases with a maximum diameter of 300 nm were obtained. Between the neighbouring Nbss phases distributed the strip shaped α/β Nb5Si3 phases. After heat treatment at 1500 °C for 4 h, the Nbss phases interconnected to form a continuous matrix with discontinuous αNb5Si3 phases. The average hardness of the SLM parts decreased from 810HV0.1 to 542HV0.1 after heat treatment. Compared with the oxide scale on arc-melted alloy, oxide scale formed on SLM-processed after oxidation at 1300 °C for 0.5 h was more compact with fewer holes, combined with the formation of a more continuous SiO2 layer at the initial oxidation stage. A layer-structured oxide scale model was presented to describe the high-temperature oxidation behavior of Nb-Si based alloy processed by SLM.
AB - Nb-18Si-24Ti-2Cr-2Al-2Hf (at%) alloy was fabricated by selective laser melting (SLM). The microstructure, hardness and oxidation behavior of Nb-Si based alloy via SLM were investigated. Results showed that the relative density of SLM alloy under the optimized processing parameters was 98.27%. The as-built alloy consisted of Nb solid solution (Nbss), αNb5Si3, βNb5Si3 and Nb3Si. Sphere shaped Nbss phases with a maximum diameter of 300 nm were obtained. Between the neighbouring Nbss phases distributed the strip shaped α/β Nb5Si3 phases. After heat treatment at 1500 °C for 4 h, the Nbss phases interconnected to form a continuous matrix with discontinuous αNb5Si3 phases. The average hardness of the SLM parts decreased from 810HV0.1 to 542HV0.1 after heat treatment. Compared with the oxide scale on arc-melted alloy, oxide scale formed on SLM-processed after oxidation at 1300 °C for 0.5 h was more compact with fewer holes, combined with the formation of a more continuous SiO2 layer at the initial oxidation stage. A layer-structured oxide scale model was presented to describe the high-temperature oxidation behavior of Nb-Si based alloy processed by SLM.
KW - Hardness
KW - Nb-Si alloy
KW - Oxidation
KW - Rapid solidification
KW - Selective laser melting
UR - http://www.scopus.com/inward/record.url?scp=84978727305&partnerID=8YFLogxK
U2 - 10.1016/j.matdes.2016.07.048
DO - 10.1016/j.matdes.2016.07.048
M3 - Article
AN - SCOPUS:84978727305
SN - 0264-1275
VL - 109
SP - 37
EP - 46
JO - Materials and Design
JF - Materials and Design
ER -