Study on Laser Consolidation of Metal Powder

The layered manufacturing technique is one of the most effective processes for the manufacture of prototypes, tools and functional end products. Selective Laser Sintering (SLS) and Selective Laser Melting (SLM), in particular, are two of the most versatile techniques, able to cover a wide range of materials such as polymer, ceramic and metal powder. In this study, the monitoring method of processing temperature at laser irradiation area by two-color pyrometer is applied. In order to investigate the consolidation characteristics of chromium molybdenum steel (SCM) based powder with a Yb:fiber laser, the maximum temperature at the irradiation area of a laser beam was measured under various experimental conditions. The influence of the scan conditions of a laser beam on the maximum temperature was evaluated. As a result, it was revealed that the maximum temperature during laser irradiation changed under the influence of laser power and scan speed of a laser beam. The maximum temperature increased with the increase of laser power, and decreased rapidly to almost at room temperature for 20 ms after the laser beam passed the center of the target area. More than the unit length 5 mm, the maximum temperature during laser irradiation was not influenced by the previous laser scan.