选择性激光熔化AlSi10Mg合金组织与性能研究
发布时间：2018-08-03 08:49
【摘要】：选择性激光熔化技术(SLM)作为一种新兴的增材制造技术,正受到越来越多的关注。选择性激光熔化铝合金的强度较传统铸造工艺有了很大的提升。但目前关于SLM AlSi10Mg合金的成型性能还有待深入研究。本论文使用选择性激光熔化技术制备了AlSi10Mg合金成型件,利用X射线衍射(XRD)、金相显微镜、扫描电镜、显微硬度计和拉伸试验机等设备,分析了SLM工艺参数和热处理工艺对成型件的组织结构、表面粗糙度、致密度及力学性能的影响。结果表明:(1)试验用Al Si10Mg合金粉末粒径分布大部分在5-45μm之间。SLM粉末平均粒径并非越小越好,粉末粒径在10μm以下会很容易被保护气体吹起,悬浮在成型腔内,这部分粉末会对激光束造成散射,干扰激光能量的正常输出,同时减少空气过滤系统的使用寿命。因此在粉末粒径的配比上,可以减少使用粒径在10μm以下的粉末。(2)选择性激光熔化Al Si10Mg合金成形件的微观形貌在激光扫描垂直截面上呈鱼鳞状,在平行激光扫描方向的面上观察呈长条状。微观组织为Si呈环岛状分布在Al的基体中,并将Al基体分割为一个个小岛状。(3)小功率180 W,激光扫描速度为800-1 000 mm/s时,试样的内部孔洞缺陷随着扫描速度增加而增加。重熔可以增加成型件的致密度减少孔洞缺陷。致密度增加了4.15%,抗拉强度增加23.21%。(4)相同热输入,高功率高扫描速度下的成型件比低功率低扫描速度具有更高的强度。激光功率为320 W,在扫描速度为1 600 mm/s时,抗拉强度达到420 MPa。(5)热处理可以显著提高成型件的显微硬度和拉伸强度。在170℃下,时效2小时之后,成型件的显微硬度可以增加15~30 HV,抗拉强度可以增加30 MPa左右。
[Abstract]:Selective laser melting (SLM) technology is becoming more and more important as a new material increasing technology. The strength of aluminum alloy melted by selective laser is much higher than that of conventional casting technology. However, the molding properties of SLM AlSi10Mg alloys need to be further studied. In this paper, AlSi10Mg alloy was fabricated by selective laser melting technique. X-ray diffraction (XRD),) metallographic microscope, scanning electron microscope, microhardness tester and tensile tester were used. The effects of SLM process parameters and heat treatment on the microstructure, surface roughness, density and mechanical properties of the molded parts were analyzed. The results show that: (1) the particle size distribution of Al Si10Mg alloy powder is mostly between 5-45 渭 m. The smaller the average particle size is, the better. The particle size below 10 渭 m can easily be blown up by protective gas and suspended in the molding cavity. This part of powder will scatter the laser beam, interfere with the normal output of laser energy, and reduce the service life of the air filter system. Therefore, the use of powder with particle size less than 10 渭 m can be reduced. (2) the microstructure of Al Si10Mg alloy formed by selective laser melting is like a fish scale on the vertical section of laser scanning. A long stripe is observed on a face parallel to the direction of the laser scanning. The microstructure of Si is distributed in the Al matrix as a ring island, and the Al matrix is divided into small islands. (3) when the laser scanning speed is 800-1 000 mm/s and the low power 180 W, the internal cavity defects increase with the increase of the scanning speed. Remelting can increase the density of the molded parts and reduce the hole defects. The density increased by 4.15 and the tensile strength increased by 23.21. (4) with the same heat input, the molding parts with high power and high scanning speed have higher strength than those with low power and low scanning speed. The laser power is 320 W, and the tensile strength reaches 420 MPA at the scanning rate of 1 600 mm/s. (5) the microhardness and tensile strength of the molded parts can be significantly improved by heat treatment. At 170 鈩，
本文编号：2161225
[Abstract]:Selective laser melting (SLM) technology is becoming more and more important as a new material increasing technology. The strength of aluminum alloy melted by selective laser is much higher than that of conventional casting technology. However, the molding properties of SLM AlSi10Mg alloys need to be further studied. In this paper, AlSi10Mg alloy was fabricated by selective laser melting technique. X-ray diffraction (XRD),) metallographic microscope, scanning electron microscope, microhardness tester and tensile tester were used. The effects of SLM process parameters and heat treatment on the microstructure, surface roughness, density and mechanical properties of the molded parts were analyzed. The results show that: (1) the particle size distribution of Al Si10Mg alloy powder is mostly between 5-45 渭 m. The smaller the average particle size is, the better. The particle size below 10 渭 m can easily be blown up by protective gas and suspended in the molding cavity. This part of powder will scatter the laser beam, interfere with the normal output of laser energy, and reduce the service life of the air filter system. Therefore, the use of powder with particle size less than 10 渭 m can be reduced. (2) the microstructure of Al Si10Mg alloy formed by selective laser melting is like a fish scale on the vertical section of laser scanning. A long stripe is observed on a face parallel to the direction of the laser scanning. The microstructure of Si is distributed in the Al matrix as a ring island, and the Al matrix is divided into small islands. (3) when the laser scanning speed is 800-1 000 mm/s and the low power 180 W, the internal cavity defects increase with the increase of the scanning speed. Remelting can increase the density of the molded parts and reduce the hole defects. The density increased by 4.15 and the tensile strength increased by 23.21. (4) with the same heat input, the molding parts with high power and high scanning speed have higher strength than those with low power and low scanning speed. The laser power is 320 W, and the tensile strength reaches 420 MPA at the scanning rate of 1 600 mm/s. (5) the microhardness and tensile strength of the molded parts can be significantly improved by heat treatment. At 170 鈩，
本文编号：2161225
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