Cai Xiaoye, Liu Tong, Yan Xuan, Cheng Zonghui, Pan Lu, Tian Zongjun, Luo Liangshun, Su Yanqing
State-Owned Wuhu Machinery Factory, Wuhu, 241007, PR China.
Anhui Key Laboratory of High-performance Non-ferrous Metal Materials, Anhui Polytechnic University, Wuhu, 241000, PR China.
Heliyon. 2022 Jun 6;8(6):e09680. doi: 10.1016/j.heliyon.2022.e09680. eCollection 2022 Jun.
In this paper, high-silicon Al-42Si alloy was prepared by selective laser melting (SLM) with different process parameters. Microstructures evolution and defects formation were studied and process parameters were optimized. The results shown that the density of SLM-fabricated Al-42Si alloy increases as input energy density increases. The highest and lowest density of SLM-fabricated Al-42Si alloy are obtained, when input energy density is 42.9J/mm and 33.8J/mm respectively. The microstructures of Al-42Si alloy fabricated by selective laser melting is mainly composed of primary silicon phase and eutectic silicon phase, which is distinct from casting alloy because of diffient grains size and shapes of the primary silicon. With higher energy density, larger size of the primary silicon observed during process due to higher heat released by powder. The size of primary silicon phase particles is in the range of 2.9-9.4μm, and the size of molten pool during SLM process is in the range of 125 ± 10μm-140 ± 10μm in this study. Also the hardness of SLM-fabricated Al-42Si alloy increases as input energy density increases between 40.0J/mm and 42.9J/mm. After heat treatment, the residual stress is eliminated, microstructure stability and homogeneous of SLM-fabricated Al-42Si alloy are improved. The silicon distribution is more uniform and sizes increases about 1∼2μm, and the hardness decreases after heat treatment. The optimal SLM parameters for Al-42Si alloy are laser power of 320W, scanning speed of 1355 mm/s, layer thickness of 50μm and scanning space of 110μm.
本文采用不同工艺参数通过选择性激光熔化（SLM）制备了高硅Al-42Si合金。研究了其微观结构演变和缺陷形成，并对工艺参数进行了优化。结果表明，SLM制备的Al-42Si合金密度随输入能量密度的增加而增大。当输入能量密度分别为42.9J/mm和33.8J/mm时，获得了SLM制备的Al-42Si合金的最高和最低密度。选择性激光熔化制备的Al-42Si合金的微观结构主要由初生硅相和共晶硅相组成，由于初生硅的晶粒尺寸和形状不同，与铸造合金不同。能量密度越高，由于粉末释放的热量越高，在过程中观察到的初生硅尺寸越大。在本研究中，初生硅相颗粒的尺寸在2.9-9.4μm范围内，SLM过程中熔池的尺寸在125±10μm-140±10μm范围内。此外，在40.0J/mm至42.9J/mm之间，SLM制备 的Al-42Si合金硬度随输入能量密度的增加而增大。热处理后，残余应力消除，SLM制备的Al-42Si合金的微观结构稳定性和均匀性得到改善。硅分布更均匀，尺寸增加约1∼2μm，热处理后硬度降低。Al-42Si合金的最佳SLM参数为激光功率320W、扫描速度1355mm/s、层厚50μm和扫描间距110μm。
