Han Guangyao, Xu Yangli, Wei Jinquan, Huang Guoqin, Li Tingting, He Yiqiang, Xie Zhiping, Mai Zihong, Yang Zeling
Institute of Manufacturing Engineering, Huaqiao University, Xiamen 361021, China.
Xiamen Institute of Software Technology, Xiamen 361024, China.
Materials (Basel). 2023 Oct 13;16(20):6683. doi: 10.3390/ma16206683.
Selective Laser Melting (SLM) is an effective technology for fabricating new types of porous metal-bonded diamond tools with complex geometries. However, due to the high cooling rate and internal stresses during SLM fabrication, defects such as high porosities and interface gaps still need to be resolved before it can be considered for use in other applications. The influence of heat treatment temperature on internal characterization, interface microstructures, and tensile properties of AlSi7Mg-bonded diamond composites fabricated by SLM were investigated in this work. From experimental results, the porosities of HT-200, HT-350, and HT-500 specimens were 12.19%, 11.37%, and 11.14%, respectively, showing a slightly lower percentage than that of the No-HT specimen (13.34%). Here, HT represents "Heat Treatment". For No-HT specimens, an obvious un-bonding area can be seen in the interface between AlSi7Mg and diamond, whereas a relative closer interface can be observed for HT-500 specimens. After heat treatment, the elastic modulus of specimens showed a relative stable value (16.77 ± 2.79~18.23 ± 1.72 GPa), while the value of yield strength decreased from 97.24 ± 4.48 to 44.94 ± 7.06 MPa and the value of elongation increased from 1.98 ± 0.05 to 6.62 ± 0.51%. This difference can be attributed mainly to the disappearance of the solid-solution hardening effect due to the increase of Si content after heat treatment.
选择性激光熔化（SLM）是一种用于制造具有复杂几何形状的新型多孔金属结合金刚石工具的有效技术。然而，由于SLM制造过程中的高冷却速率和内应力，在考虑将其用于其他应用之前，仍需解决诸如高孔隙率和界面间隙等缺陷。本研究调查了热处理温度对通过SLM制造的AlSi7Mg结合金刚石复合材料的内部特征、界面微观结构和拉伸性能的影响。实验结果表明，HT-200、HT-350和HT-500试样的孔隙率分别为12.19%、11.37%和11.14%，略低于未热处理试样（13.34%）。这里，HT表示“热处理”。对于未热处理试样，在AlSi7Mg与金刚石的界面处可看到明显的未结合区域，而对于HT-500试样，可观察到相对紧密的界面。热处理后，试样的弹性模量显示出相对稳定的值（从16.77±2.79 GPa到18.23±1.72 GPa），而屈服强度值从97.24±4.48 MPa降至44.94±7.06 MPa，伸长率值从1.98±0.05%增加到6.62±0.51%。这种差异主要可归因于热处理后Si含量增加导致固溶强化效应消失。
