选择性激光熔融增材制造不锈钢力学性能研究进展及统计分析

Research progress and statistical analysis of mechanical properties of selective laser-melted stainless steel

在简要介绍金属增材制造技术分类的基础上,对选择性激光熔融(SLM)技术的研究进展进行梳理,以SLM制品的力学性能及其主要影响因素为重点进行综述。通过SLM技术制备了48个316L不锈钢试样,通过单轴拉伸试验获得了弹性模量、屈服强度、抗拉强度、延伸率和泊松比等基本力学性能数据。采用SPSS软件分析了力学性能试验数据的分布规律,并通过方差分析和非参数检验方法研究了设备、试样方向和厚度对力学性能的影响。结果表明:不同组试样的力学性能具有较为明显的差异;现有的修正R-O和G-R-O不锈钢本构模型能够较好地拟合试验的应力-应变曲线;弹性模量、泊松比以及屈服强度基本符合正态分布规律,而对应塑性阶段的抗拉强度和延伸率与正态分布相差较大。同时,给出了各组试样的力学性能平均值和具有95%保证率的参考值范围,可供实际应用参考。

Based on a brief summary of the classification of metal additive manufacturing technology, the research progress of selective laser melting(SLM) technology was reviewed, focusing on the mechanical properties of SLM products and their main influencing factors. 48 samples of 316 L stainless steel were prepared by SLM technology, and the basic mechanical properties including elastic modulus, yield strength, ultimate strength, elongation and Poisson’s ratio were obtained through uniaxial tensile tests. SPSS software was used to analyze the statistic distribution of mechanical properties and the influence of equipment, direction and thickness on mechanical properties through variance analysis and non-parametric test. It is shown that the mechanical properties of test samples in different groups have obvious differences. The current constitutive model for stainless steel including modified R-O model and G-R-O model can fit the test stress-strain curves. The elastic modulus, Poisson’s ratio and yield strength basically follow the normal distribution, while the ultimate strength and elongation of the corresponding plastic stage differ greatly from the normal distribution. The mean values of mechanical properties and the range of reference values with 95% confidence level are given, which can be used as reference for practical application.