Research on micro-porous surface forming process based on selective laser melting
LI Pei1，QIAN Bo1，ZHANG Chi1，ZHANG Jian-rui1，WEI Qing-song2
1 School of Mechanical and Power Engineering, East China University of Science and Technology, Shanghai 200237, China，2 School of Materials Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074, China
Abstract：Microporous surfaces can enhance boiling heat transfer and have broad industrial application prospects. Selective laser melting (SLM) is a new manufacturing method for microporous surfaces. The effects of scanning spacing and laser power on 316L stainless steel powder forming micro-porous surface during SLM process were mainly studied. The results show that the pores on the surface of the micro-porous formed by scanning spacing of 0.3-0.5 mm are regular through holes, and a large number of powder bonds exist on the inner wall of the holes, which can form a large number of potential gasification cores. Using 180-240 W laser power and 0.2-0.5 mm scanning spacing, a micro-porous surface with hydraulic diameter of 78.9-410.5 μm and porosity of 11.6%-50.2% is obtained. The boiling heat transfer experiment was carried out with deionized water. The initial boiling temperature of the micro-porous surface formed by 240 W laser power and 0.5 mm scanning spacing is 104 ℃, and the critical heat flux is 150 W/cm2, which has obvious boiling heat transfer enhancement effect.
2019, Vol. 29 
