In the present work, a new hydrogen added argon heat treatment process that prevents the formation of hydrides and eliminates the dehydrogenation step, is developed. Dissolved hydrogen has a good effect on sintering properties such as oxidation resistance and density of greens. This process can also reduce costs and processing time. In the experiment, commercially available Ti-6Al-4V powders are used. The powders are annealed using tube furnace in an argon atmosphere at 700oC and 900oC for 120 min. Hydrogen was injected temporarily during argon annealing to dissolve hydrogen, and a dehydrogenation process was performed simultaneously under an argon-only atmosphere. Without hydride formation, hydrogen was dissolved in the Ti-6Al-4V powder by X-ray diffraction and gas analysis. Hydrogen is first solubilized on the beta phase and expanded the beta phases’ cell volume. TGA analysis was carried out to evaluate the oxidation resistance, and it is confirmed that hydrogen-dissolved Ti-6Al-4V powders improves oxidation resistance more than raw materials.

Machining processes generate severe heat, which deforms thin metallic parts while they are being processed. The amount of deformation of a thin part is mainly dependent on heat and the shape of a component. The selection of machining parameters can decrease the temperature arisen during a machining process. This paper investigates selecting machining parameters to minimize the heat-deformation that is produced during machining. Taguchi method is applied to setup experiments. Three factors and three levels for each factor in the experimental design are selected. This research analyzes the effects of machining parameters to minimize the heat-deformation through examining the analysis of variance (ANOVA) and the signal to noise ratio (S/N).