Method to select defocused amount and Z-increments in forming thin-walled part with laser cladding

Defocused amount and Z-increments affect the accuracy and efficiency of thin-walled part with laser cladding forming. The key to obtain high-accuracy thin-walled part is to make the Z-increments equal the cladding height under initial defocused amount. In order to solve the problem of forming thin-walled part with high accuracy and efficiency, powder density distribution model of laser cladding system with coaxial-powder feeding is established based on the probability theory, the calculation formula of cladding height under different negative defocused amounts is given and experimentally verified. The calculation method of multi-layer cladding forming thin-walled part height under any negative defocused amount and Z-increment is proposed and experimentally verified. The results show that calculations of multi-layer cladding forming thin-walled part height are in accordance with experiments. Selecting self-regulation-effect negative defocused amount as large as possible, and making Z-increments equal the calculated value of cladding height under this defocused amount, the thin-walled parts with high forming efficiency and high accuracy can be obtained.