大幅面激光选区熔化成型仓流场特性研究

Study on Flow Field Characteristics of Large Format Selective Laser Melting Forming Bin Structures

采用Fluent仿真软件,建立多种典型大幅面成型仓结构,通过SpaceClaim软件对建立的大幅面成型仓进行流场抽取,获取激光选区熔化成型仓内部的流体域,并根据成型台面上方位置以及激光镜头下方位置,对多种结构进行流场特性及流场均匀性分析.研究结果表明,多孔风墙成型仓内部形成稳定均匀的气体流场,在成型台面上方20 mm处,流速为284~308 mm/s;在激光镜头下方位置处,整体保护气体流速为142~175 mm/s;并且内部可以形成一个从进口到出口的循环气流,将没有及时排出的烟尘在多次流动后排出成型仓.

Fluent simulation software is used to establish a variety of typical large-format forming bin structures,and SpaceClaim software is used to extract the flow field of the established large-format forming bin,to obtain the fluid domain inside the laser-selective melting forming bin,and to conduct flow field characteristics for various structures.The positions above the forming table and below the lens are used to analyze the flow field characteristics and flow field uniformity of various structures.The research results show that a stable and uniform gas flow field is formed inside the porous wind wall forming bin.At 20 mm above the top of the forming table,the flow rate is in the range of 284~308 mm/s;At the position below the laser lens,the overall shielding gas rate is in the range of 142~175 mm/s;and a circulating gas flow from the inlet to the outlet can be formed inside,and the soot that is not discharged in time can be discharged out of the forming bin after multiple flows.