Development of High Purity Tungsten Material高純度タングステン材料の開発
high-purity, tungsten, 5N, density, direct sinter, HP, HIP, re-crystallization, deform, high temperature, mechanical properties
High-purity tungsten powder in the grade of 99.999%(5N) was sintered and fabricated. Its sintering properties were so good as to get achieve high density by direct sinter, HP or HIP. Sintered high-purity tungsten can be used to make plates, bars and wire, so we expect them to be applied as spattering targets for the LSI industry or as electrodes for discharge lamps. High-purity tungsten tends to re-crystallize at lower temperature than the doped tungsten, because it has less pores, which have caused by impurities and prevent the re-crystallization. At high temperature, high-purity tungsten is easy to deform than the doped tungsten, and at room temperature, its mechanical properties tend to decrease after being heated.