Research on a New SLM Process of Pre-melting and Re-melting
-
摘要: SLM（Selective laser melting）工艺是增材制造领域发展较为迅猛的一种工艺，其在复杂金属结构零件的制造领域具有极大的优势。为了降低SLM工艺的孔隙率，获得更高的致密度，以及更好的机械性能（硬度），提出了一种新型工艺，先对粉末层进行低激光功率的预熔处理，然后使用高功率的激光再次熔化，实现逐层重熔。8组对比试验结果表明：与只经过单熔处理的零件相比，经过预熔与重熔两次熔化后的零件，孔隙率从0.186%减少到0.039%，硬度从237.5 HV提高到264.3 HV，组织均匀性提高，组织呈马氏体结构。由此说明，SLM实时预熔重熔成型工艺在复杂金属结构零件的制造领域，具有较好的应用前景。Abstract: Selective laser melting (SLM) is an attractive manufacturing technique for producing metal parts with complex geometries and high performance. The powder materials used in this study was 316L stainless steel powder. In order to reduce porosity, obtain higher density and better mechanical properties (hardness), a new process was proposed. The powders were pre-melted by using the low laser power, then the powders were melted again by using the high power laser to realize the re-melting process layer by layer. The results show that the porosity decreases from 0.186% to 0.039%, and the hardness value increases from 237.5 HV to 264.3 HV after pre-melting and re-melting. The homogeneity of martensite is improved. It shows the new process had a great prospect for manufacturing the complex metal parts.
-
Key words:
- pre-melting /
- re-melting /
- porosity /
- microstructure /
- hardness
-
表 1 对比试验参数
样件编号 1 2 3 4 5 6 7 8 预熔功率/W 无 120 150 180 210 210 210 210 重熔功率/W 210 210 210 210 210 240 270 300 
下载: 导出CSV
-
[1] 付立定, 史玉升, 章文献, 等.316L不锈钢粉末选择性激光熔化快速成形的工艺研究[J].应用激光, 2008, 28(2):108-111 doi: 10.3969/j.issn.1000-372X.2008.02.005Fu L D, Shi Y S, Zhang W X, et al. The process research of 316L stainless steel in selective laser melting[J]. Applied Laser, 2008, 28(2):108-111(in Chinese) doi: 10.3969/j.issn.1000-372X.2008.02.005 [2] 赵灿, 张佳, 刘锦辉.选择性激光熔化316L不锈钢粉成形优化工艺[J].黑龙江科技学院学报, 2013, 23(1):47-50 doi: 10.3969/j.issn.1671-0118.2013.01.011Zhao C, Zhang J, Liu J H. Selective laser melting of 316L stainless steel powder molding process optimization[J]. Journal of Heilongjiang Institute of Science and Technology, 2013, 23(1):47-50(in Chinese) doi: 10.3969/j.issn.1671-0118.2013.01.011 [3] Liverani E, Toschi S, Ceschini L, et al. Effect of selective laser melting (SLM) process parameters on microstructure and mechanical properties of 316L austenitic stainless steel[J]. Journal of Materials Processing Technology, 2017, 249:255-263 doi: 10.1016/j.jmatprotec.2017.05.042 [4] Liu Q, Wang Y D, Zheng H, et al. Microstructure and mechanical properties of LMD-SLM hybrid forming Ti6Al4V alloy[J]. Materials Science and Engineering:A, 2016, 660:24-33 doi: 10.1016/j.msea.2016.02.069 [5] Olakanmi E O, Cochrane R F, Dalgarno K W. A review on selective laser sintering/melting (SLS/SLM) of aluminium alloy powders:processing, microstructure, and properties[J]. Progress in Materials Science, 2015, 74:401-477 doi: 10.1016/j.pmatsci.2015.03.002 [6] Almangour B, Grzesiak D, Yang J M. Scanning strategies for texture and anisotropy tailoring during selective laser melting of TiC/316L stainless steel nanocomposites[J]. Journal of Alloys and Compounds, 2017, 728:424-435 doi: 10.1016/j.jallcom.2017.08.022 [7] Suryawanshi J, Prashanth K G, Ramamurty U. Mechanical behavior of selective laser melted 316L stainless steel[J]. Materials Science and Engineering:A, 2017, 696:113-121 doi: 10.1016/j.msea.2017.04.058 [8] Lamikiz A, Sánchez J A, de Lacalle L N L, et al. Laser polishing of parts built up by selective laser sintering[J]. International Journal of Machine Tools and Manufacture, 2007, 47(12-13):2040-2050 doi: 10.1016/j.ijmachtools.2007.01.013 [9] Sun Z J, Tan X P, Tor S B, et al. Selective laser melting of stainless steel 316L with low porosity and high build rates[J]. Materials & Design, 2016, 104:197-204 http://www.wanfangdata.com.cn/details/detail.do?_type=perio&id=81b7d4283d5c821d0fd8e2ebd817986b [10] 钱波, 张李超, 史玉升, 等.基于STL模型的表面区域递归拾取算法[J].华中科技大学学报:自然科学版, 2008, 36(9):90-93 http://d.old.wanfangdata.com.cn/Periodical/hzlgdxxb200809024Qian B, Zhang L C, Shi Y S, et al. Surface region recurrence picking up algorithm based on stereolithography model[J]. Journal of Huazhong University of Science and Technology:Nature Science, 2008, 36(9):90-93(in Chinese) http://d.old.wanfangdata.com.cn/Periodical/hzlgdxxb200809024 [11] Yasa E, Deckers J, Kruth J P. The investigation of the influence of laser re-melting on density, surface quality and microstructure of selective laser melting parts[J]. Rapid Prototyping Journal, 2011, 17(5):312-327 doi: 10.1108/13552541111156450 [12] Wang D, Wu S B, Fu F, et al. Mechanisms and characteris-tics of spatter generation in SLM processing and its effect on the properties[J]. Materials & Design, 2017, 117:121-130 https://www.sciencedirect.com/science/article/pii/S0264127516315866 [13] Choi J P, Shin G H, Brochu M, et al. Densification behavior of 316L stainless steel parts fabricated by selective laser melting by variation in laser energy density[J]. Materials Transactions, 2016, 57(11):1952-1959 doi: 10.2320/matertrans.M2016284 [14] Cherry J A, Davies H M, Mehmood S, et al. Investigai-tion into the effect of process parameters on microstructural and physical properties of 316L stainless steel parts by selective laser melting[J]. The International Journal of Advanced Manufacturing Technology, 2015, 76(5-8):869-879 doi: 10.1007/s00170-014-6297-2 [15] Liu Y, Yang Y Q, Wang D. A study on the residual stress during selective laser melting (SLM) of metallic powder[J]. The International Journal of Advanced Manufacturing Technology, 2016, 87(1-4):647-656 doi: 10.1007/s00170-016-8466-y -
点击查看大图
图(9) / 表(1)
计量
- 文章访问数: 433
- HTML全文浏览量: 84
- PDF下载量: 107
- 被引次数: 0
