고압 수 분사법을 통해 제작된 선택적 레이저 용융 가공법용 Ni-Cr계 금속 분말의 특성 분석

The selective laser melting (SLM) process for dentistry is one of the additive manufacturing technologies (AM). The SLM process facilitates producing a three-dimensional model rapidly in a complex shape by directly melting metal powder. This process generates the detailed items of a three-dimensional model shape. In this connection, it consolidates a thin powder layer through selective melting process and laser beam. In regard to the SLM process, various types of powder have been examined. They were Fe-base powder, Ti-6Al-4V powder and Al-base powder, just to name a few. It is believed that the aforementioned technologies will be widely utilized to produce metal parts based on the metal powder raw materials. This study chose Ni-Cr metal powder to produce metal powder materials used in the SLM process for dentistry. Among the metal powder production technologies, this study specifically made use of the high-pressure water atomized technology to produce the metal powder. The purpose of this study was to examine the powder ad preliminary data of Ni-Cr metal powder. Also, this study aimed to produce and utilize actual metal powder based on the results of examination. This study obtained the following conclusions within the experimental limitations. This study found the mean particle size of Ni-Cr metal powder to be 37.65 μm. The Ni-Cr metal powder was produced using the high-pressure water atomized technology under the following conditions: 1. water atomization flux of 300 liter/min, 2. hydraulic pressure of 400 kgf/cm2 and 3. injection angle of 45°. This study confirmed that the grain form of powder (solid particle form) would vary depending on the production process. Specifically, the aforementioned findings confirmed that the metal powder produced based on the high-pressure water atomized technology would depend on the powder surface oxidation behavior during the production process. Moreover, the metal powder form was dependent on the process parameters. Also, metal powder equivalent to a particle size of 37 μm could be obtained in a very short period of time. Hence, the laser process using Ni-Cr powder produced based on this process is expected to be used in a wide range of applications for the dental industry.