抄録
In order to manufacture the part of a small lot at lower cost and shorter lead-time, various techniques, such as a rapid tooling, reverse engineering and high speed milling, are proposed. Recently, milling-combined laser metal sintering system, which is the device of sintering the metal powder and milling the sintered metal with end mill at the one process, has been developed to produce the injection molding dies. In this report, the sintering characteristics of the metal powder used for rapid tooling with Yb fiber laser are described. Relationship between the scanning speed of laser beam and the width of sintered material on the different surface plate are investigated. Moreover, the cross section of sintered material is analyzed with EPMA and cutting force is measured by the dynamometer in the various conditions.
As a result, it was shown that the suitable irradiation energy for laser sintering should be selected to obtain the good shaped structure, which is occurred the melting, the cohesion and the solidification of the metal powder repeatedly. The shape of sintered material is formed like a spherical in the conditions of too much energy supply, and not formed partially in the conditions of a little energy supply. The melted metal powder with the generated heat by laser irradiation alloyed with the plate surface on the process of the solidification. The specific cutting force of sintered material on the surface with sandblast is quite larger than that on the standard surface by the difference of the wetting of melted metal powder.
