Wang Siyu, Liu Changsheng
School of Material Science and Engineering, Northeastern University, Shenyang 110819, China.
Materials (Basel). 2019 Aug 19;12(16):2637. doi: 10.3390/ma12162637.
The composition distribution can influence the performances of laser cladding layers. Hence, the technology of rthe eal-time monitoring of chemical composition is required to apply on laser cladding process. In this experiment, four kinds of Ni-based alloy powders were used to prepare laser cladding layers on AISI (American Iron and Steel Institute) 4140 steel. At the same time, emission spectra were collected during real-time laser cladding process. The intensity of spectral lines were revised with a corrected number deduced with evaporation rate of elements. By correlating the weight ratios of elements with the intensity ratios of spectral lines, four calibration curves were established to monitor composition distribution. The main results are shown as following: Weight ratios among elements in the laser cladding layers changed versus input energy density due to different saturated vapor pressures among elements; the dilution amount of substrate showed weak relations under the different manufacturing parameters, and the main reason for this can be attributed to the change of thermo-physical properties among different Ni-based alloy powders; the predicted results showed that when the composition concentration was higher than 3 wt.%, the relative error was lower than 8%, compared with EDS (Energy-dispersive X-ray spectroscopy) testing data.
成分分布会影响激光熔覆层的性能。因此，化学成分实时监测技术需要应用于激光熔覆过程。在本实验中，使用了四种镍基合金粉末在AISI（美国钢铁协会）4140钢上制备激光熔覆层。同时，在实时激光熔覆过程中采集发射光谱。谱线强度用根据元素蒸发速率推导的校正数进行修正。通过将元素的重量比与谱线强度比相关联，建立了四条校准曲线以监测成分分布。主要结果如下：由于元素间不同的饱和蒸气压，激光熔覆层中元素间的重量比随输入能量密度而变化；在不同制造参数下，基体的稀释量关系较弱，主要原因可归因于不同镍基合金粉末间热物理性能的变化；预测结果表明，当成分浓度高于3 wt.%时，与能谱（能量色散X射线光谱）测试数据相比，相对误差低于8%。
