中文摘要：

选区激光熔化（SLM）技术是一种典型的快速成形技术,使用高能激光束熔化金属粉末,逐层堆积,直接成形复杂高性能金属零部件。为了对SLM成形多孔铝合金的性能进行研究,利用扫描电子显微镜、能量色散X射线荧光光谱、纳米压痕等测试手段分析了多孔铝合金的表面形貌、孔隙率、显微组织、相组成及微观力学性能。结果表明,激光功率为130 W时,孔隙率达到最大,多孔合金的显微组织细化,晶粒尺度达到纳米级别;激光功率变化对多孔铝合金的纳米硬度影响较大,但对弹性模量的影响不明显,其中α-Al相的弹性模量约为65 GPa,α-Al＋Si共晶组织相的弹性模量约为85 GPa。

英文摘要：

Selective laser melting（SLM） is a typical rapid forming technique, and complex metallic components with high performance are fabricated directly by using high energy laser beam for melting the metallic powder and layer-by-layer deposition. To investigate the properties of porous aluminum alloy fabricated by SLM, surface morphology, porosity, microstructure, phase composition and micro-mechanical properties of porous aluminum alloy are studied by the scanning electron microscope, energy dispersive X-ray spectroscopy and nanoindentation.The results show that the porosity of the porous aluminum alloy reaches its maximum, the microstructure is refined and the grain size reaches the nanometer level when the laser power is 130 W. The nano hardness of the porous aluminum alloy changes with laser power, while the the elastic modulus does not change obviously. The elastic modulus of the α-Al phase is around 65 GPa, and the elastic modulus of the α-Al＋Si phase is around 85 GPa.