中文摘要：

采用同轴送粉激光近净成形系统，研究同轴送粉粉末分布特征，开展氧化铝（Al2O3）陶瓷薄壁件成形实验，结合粉末分布密度函数分析光斑直径和激光功率对激光近净成形Al2O3陶瓷薄壁件表面形貌的影响。结果表明，同轴送粉粉末成双重高斯分布，激光光斑大小影响光束直接辐照粉末量，进而影响薄壁件表面形貌，光斑大小与光束直接辐照粉末量成高斯积分函数；增大激光功率可减弱高斯分布粉末对激光能量分布的影响，有利于获得较好的表面形貌，但激光功率过大会导致薄壁件表面形貌变差；采用合理的工艺参数成形的Al2O3陶瓷件相对密度可达99.72%。

英文摘要：

Al2O3 thin- wall ceramic is formed by laser engineered net shaping and distribution of coaxial powder is obtained using tapes. A function is found to be related to the distribution of powder density. Based on this function, the influence of laser spot size and laser power on the surface morphology of thin-wall Al2O3 ceramic is analyzed. The results show that the distribution of coaxial feeding powder is in keeping with the double Gaussian distribution. Laser spot size directly affects the powder utilization, and thereby affects the surface morphology of thin- wall parts. There is a Gaussian integral function between the laser spot size and the quantity of powder irradiated by laser beam. The results also demonstrate that high laser power can weaken the influence of powder on laser energy distribution, which can improve the surface morphology of thin- wall parts, but the surface morphology is bad if the laser power is too high. The relative density of the Al2O3 ceramic is up to 99.72% with suitable process parameters.