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We report on a novel synthetic method of microwave processing with a domestic 2450MHz microwave synthesis system to prepare ZnO fiber using pure ZnO powder. We also studied and report on structure and morphology of the resultant products by XRD and SEM. XRD revealed that a single phase ZnO fiber can be synthesized quickly and easily by microwave processing. The results indicate that microwave processing is a promising method of processing ZnO fiber.

Strontium hexaferrite powder synthesised conventionally has been treated in nitrogen atmosphere and subsequently calcined in air (Nitrogen Treatment and Re-calcination : NTR Process). The phase identification studies by means of X-ray diffraction (XRD) showed decomposition of strontium hexaferrite and reduction of the resultant iron oxide (Fe₂O₃) during the reaction with nitrogen. According to high resolution scanning electron microscopy (HRSEM) studies, reduction during nitrogenation, resulted in the division of some big grains into much finer sub-grains, strontium hexaferrite, Fe₃O₄ and Sr₇Fe₁₀O₂₂ were the main phases obtained after reduction. The hexaferrite phase reformed on subsequent calcination. The magnetic measurements indicated a significant decrease in the intrinsic coercivity during nitrogenation due to the formation of Fe₃O₄. However, after a re-calcination process, the remanence and maximum magnetisation (i.e. magnetisation at 1100 kA/m ) exhibited values close to the initial values before treatment but the value of the intrinsic coercivity was higher than that prior to nitrogenation. The microstructure showed that this could be attributed to very fine grains which originated from the fine sub-grains formed during nitrogenation.

The selected temperature was 950°C for nitrogenation and 1000°C for re-calcination. The time and initial pressure were selected to be 5 hours and 1 bar respectively. The highest coercivity obtained after re-calcination was 340 kA/m.

Mechanical alloying (MA) as a powder metallurgy method is often used to prepare materials with ultrafine grain and special structure difficultly obtained in conventional ways. In this paper, the TiH₂45Al4Sn (at. %) composite powder was mechanically milled by high energy ball milling. The crystalline grain size, morphology and phase characteristic of milled powder with different milling time were investigated by XRD, SEM and TEM. The results show that with the milling time increasing, the powder particles are refined rapidly in the initial stage and then gradually become stable. The new phase Ti₂Sn₃ is formed by mechanical alloying (MA) of TiH₂, Al, Sn powders during milling which resulted particles refinement to very small size. The homogeneous and dense Ti₂Al and Ti₂Sn₃ intermetallic compounds are obtained after vacuum hot pressing sintering, which microstructure is composed of equal axial Ti₂Al as matrix and fine Ti₂Sn₃ particles. Because of the addition of Sn, Ti-Al intermetallic compounds formation is inhibited during MA and sintering. However, Sn contributes to the formation of Ti₂Al phase which which is difficult to be obtained with the conventional method of casting and forging.