Abstract
The layered manufacturing technique is one of the most effective processes for the manufacture of prototypes, tools and functional end products. A variety of components, such as polymer, ceramic, paper and metal powder, has been applied to date for the achievement of manufacturing objectives. Selective Laser Sintering (SLS) and Melting (SLM), in particular, are two of the most versatile techniques, able to cover a wide range of materials. In this study, in-process monitoring of the processing temperature at laser irradiation spot is proposed by using two-color pyrometer, which has been developed by the authors. In order to investigate the consolidation characteristics of chromium molybdenum steel (SCM) based powders with a Yb fiber laser, the maximum temperature at the irradiation spot of a laser beam was measured under various experimental conditions. The influence of the laser power and diameter of laser beam on the temperature were evaluated. As a result, it was revealed that the maximum temperature during laser irradiation changed under the influence of laser power and particle size of powders. The temperature increased with the increase of laser power, and was greatly influenced by the particle size of the powders. The temperature after laser irradiation decreased rapidly to room temperature.
