建立了按激光光斑直径逐点沉积热力耦合的热应力有限元分析模型. 316L不锈钢直薄壁件沉积过程的热应力模拟结果显示,拉应力区出现在基板与沉积部分界面处(界面拉应力区)和沉积部分顶部(顶部拉应力)；拉应力区的位置随激光束的运动不断变化. 实验证明, 沉积过程中的开裂分别发生在沉积部分顶部(顶部开裂)和基板与沉积部分界面处的边缘部位(边缘开裂). 顶部开裂出现在顶部拉应力区, 边缘开裂出现在界面拉应力区中拉应力最大的边缘部位. 有限元模拟结果很好地解释了实验中的开裂现象.
Abstract. RP/M is an advance technology based on build-up and discrete idea, and Laser direct deposition by coaxially feeding the powders to laser melting pool is a RM technology in general use. It is a critical problem found in this technology that the thermal stress result in the cracking and residual stress. The finite element model of the thermal stress is created in the paper by the use of thermal force coupling method According to laser spot diameter and pointwise deposition. The simulating results depositing vertical thin wall sample of 316L stainless steel have exhibited that the tensile stress presents in the position located at interface joining the substrate on depositing layer（named as interface tensile stress zone）and the top of the depositing layer (named as top tensile stress zone), and the position of those tensile stress zones continue to vary along with the movement of laser beam. The experiment observation demonstrates that the cracking during depositing process individually occur on the top of depositing layer (named as top cracking) and edge positions located at interface joining the substrate on depositing layer（named as edge cracking）.The top cracking occurs in the top tensile stress zone, and edge cracking occurs in the edge positions with maximum tensile stress in the interface tensile stress zone. The simulating results give an appropriate explanation for the cracking phenomenon during depositing the vertical thin wall sample, and that the validation of finite element model and the accuracy of the simulating results have been illustrated.
参考文献
| [1] | |
| [2] | |
| [3] |
- 下载量()
- 访问量()
- 您的评分：
-
10%
-
20%
-
30%
-
40%
-
50%