选区激光熔化中激光束的传输变换及聚焦特性

Laser beam's focused properties and its transmission and transformation in selective laser melting

为了获得光束质量较好、光斑尺寸较小、功率密度较高的、适合于在选区激光熔化快速成型技术中应用的激光束,对应用于选区激光熔化快速成型技术中的高斯光束进行传输与变换。对其传输变换及聚焦特性进行了理论分析与实验验证,实验结果与理论分析的结果相符。取得了功率密度达106W/cm2以上的、光斑尺寸较小的、满足于在选取激光熔化技术中应用的光斑。将其应用于镍基合金(N i25)和铜磷合金粉末的三维选区激光熔化快速成型。结果表明,这种传输变换及聚焦特性是可行有效的,得到了满足要求的光斑尺寸和功率密度。

In order to obtain the laser beam with better beam quality, smaller spot diameter and higher power density in rapid prototyping for selective laser melting （ SLM ）, Gaussian beam used in SLM was transmitted and transformed. The theoretic and experimental transmission, transformation and focused characteristic properties were analyzed. The experimental results are consistent with the theoretic ones. The smaller spot with power density above 106W/cm^2 which is applicable in SLM, was obtained. When used in 3-D rapid prototyping for SLM of Ni-based alloy and Cu-P alloy powder, it also indicated feasible and effectual, and met the demands of spot diameter and power density.