中文摘要：

为了消除激光金属直接成形DZ125L高温合金薄壁件中的裂纹,研究了激光扫描方式对薄壁件（单道多层）熔覆层应力分布和开裂的影响。对比了两种扫描方式（单向扫描和往复扫描）对薄壁件的应力分布和开裂的影响。模拟和实验结果表明,单向扫描方式下薄壁件的应力分布不均匀,引起薄壁件的两端出现严重的翘曲且中间部分出现裂纹;往复扫描方式下薄壁件的应力分布相当均匀,没有出现翘曲和裂纹,熔覆层表面比较平整。

英文摘要：

The effect of scanning methods on stress distribution and cracking of the DZ125L superalloy thin-wall structures is investigated numerically and experimentally.The results demonstrate that the stress distribution is not uniform in single-direction scanning method,which leads to warping in both sides of the structures and cracking in the middle regions.However,in back-and-forth scanning method,the stress distribution is relatively uniform,and the fabricated parts have smooth surface without any warping or cracking.