摘要
The selective laser melting(SLM) method has a great potential for fabricating injection mold with complex structure. However, the microstructure and performance of the SLM molds show significantly di erent from those manufac?tured by traditional technologies. In this study, the microstructure, hardness and especially corrosion behavior of the samples fabricated by SLM and casting were investigated. The XRD results exhibit that the γ?Fe phase is only obtained in the SLM parts, and the α?Fe peak slightly moves to low di raction angle compared with casting counterparts. Due to the rapid cooling rate, the SLM samples have fine cellular microstructures while the casting ones have coarse grains with obvious elements segregation. Besides, the SLM samples show anisotropy, hardness of side view and top view are 48.73 and 50.31 HRC respectively, which are 20% higher than that of casting ones. Corrosion results show that the SLM samples have the better anti?corrosion resistance(in a 6% FeCl3 solution for 48 h) but the deeper corrosion pits than casting ones. Finally, the performance of the SLM molds could meet the requirement of injecting production. Moreover, the molds especially present a significant decrease(20%) of cooling time and increases of cooling uniform?ity due to the customized conformal cooling channels.
The selective laser melting(SLM) method has a great potential for fabricating injection mold with complex structure. However, the microstructure and performance of the SLM molds show significantly di erent from those manufac?tured by traditional technologies. In this study, the microstructure, hardness and especially corrosion behavior of the samples fabricated by SLM and casting were investigated. The XRD results exhibit that the γ?Fe phase is only obtained in the SLM parts, and the α?Fe peak slightly moves to low di raction angle compared with casting counterparts. Due to the rapid cooling rate, the SLM samples have fine cellular microstructures while the casting ones have coarse grains with obvious elements segregation. Besides, the SLM samples show anisotropy, hardness of side view and top view are 48.73 and 50.31 HRC respectively, which are 20% higher than that of casting ones. Corrosion results show that the SLM samples have the better anti?corrosion resistance(in a 6% FeCl3 solution for 48 h) but the deeper corrosion pits than casting ones. Finally, the performance of the SLM molds could meet the requirement of injecting production. Moreover, the molds especially present a significant decrease(20%) of cooling time and increases of cooling uniform?ity due to the customized conformal cooling channels.
基金
National Natural Science Foundation of China(Grant No.51605176)
National Hi-tech R&D Program of China(863 Program,Grant No.2015AA042501)
Hubei Provincial Natural Science Foundation of China(Grant No.2018CFB502)
Guangdong Provincial Technology Major Project of China(Grant No.2017B090911007)
State Key Laboratory of Materials Processing and Die&Mould Technology,Huazhong University of Science and Technology(Grant No.P2019-006)
Engineering Research Center of Rock-Soil Drilling&Excavation and Protection,Ministry of Education(Grant No.201804)
