In this study, the ZnS composite powders for host material in phosphor was synthesized in situ by mechanical alloying. As the mechanical alloying time increases, particle size of ZnS decreases. ZnS powders of in a mean size was fabricated by mechanical alloying for 10h. The crystal structures of ZnS powders were investigated by X-ray diffraction and the photo-luminescence properties was evaluated with the optical spectra analyzer. The steady state condition of mechanically alloyed ZnS was obtained as a mean particle size of in 5h milling. The sphalerite and wurtize structures coexist in the ZnS mechanically alloyed for 5h. The ZnS powder mechanically alloyed for 10h grows to the sphalerite structure. And the strong emission peaks of ZnS are observed at 480 nm wave length at the powders of mechanically alloyed for 10h, but the sphalerite and wurtize structures in ZnS coexist and emission peaks are not appeared at the powders of mechanically alloyed for 10h.
This paper deals with the fabrication of titanium carbide using fine titanium hydride. The ratio of and C (Activated carbon) was 1:1 (mol) and milled in a planetary ball mill at a ball-to-powder weight ratio of 20:1. Thereafter, TGA was performed at to observe change of weight with milling time. Titanium carbide was obtained by using tempering the milled powders at . The microstructures of titanium carbide as well as the change of the lattice parameters and particle size have been studied by X-ray diffraction (XRD) and scanning electron microscopy (SEM).
The application concept of using a fail safety filter on the filtering system is to prevent the particle leakage when the main filter element is broken at high temperature. In this study, the metal filters were fabricated by pressureless sintering method. The mixture of stainless steel powders and filler metal binder solved in the water solutions of 5% PVA was compacted to form the cylindrical filter without pressure. The compacted filter were sintered in the vacuum sintering furnace at 120 for 1 hour. The metal filter(produced with powder of 640-840 size) having more than above 50% porosity, 500 pore size, and permeability of 7.310m plugged within 2.5 minute to prevent the leakage of maximum slip particle size of less than 3.