Laser Beam Shaping in Laser Powder Bed Fusion Additive Manufacturing

激光粉末床熔融（LPBF）是最有前途的工业金属增材制造（AM）技术之一。在这个过程中，物体的产生是通过激光熔化金属粉末的薄层（粉末床）的选择区域。由于金属粉末对激光具有固有的低吸收率，在实践中观察到有限的激光-材料耦合，导致LPBF的生产率和材料可用性显著下降。这个项目将通过在激光束整形的帮助下研究新的能量分布来解决这一挑战。使用激光束整形导致特定的辐照度分布和相位，这可以通过减少热梯度来提高工艺的生产率以及零件的热历史，从而减少残余热应力或晶粒取向和尺寸。

Laser powder-bed fusion (LPBF) is one of the most promising industrial metal Additive Manufacturing (AM) techniques. In this process, the creation of an object occurs by laser melting of selective areas of thin layers of metallic powders (the powder bed). As metallic powders possess intrinsic low absorptivity of the laser light, limited laser-material coupling is observed in practice resulting in significant debits in productivity and materials availability for LPBF. This project will tackle this challenge by investigating new energy distribution with the help of Laser Beam Shaping. The use of a Laser Beam Shaping leads to specific irradiance distribution and phase which could improve the productivity of the process as well as the thermal history of the parts by reducing thermal gradients, thus decreasing the residual thermal stress, or the grain orientation and size.