The effects of sintering in vacuum and Ar atmosphere on the magnetic performance and microstructure of NdFeB magnet were studied. The results show that there is a great individual difference of magnetic performance among vacuum sintered samples,but the Ar sintered samples are almost of uniform magnetic performance. The average remanence and magnetic energy product of the magnet by Ar atmosphere sintering are about 0.05-0.09 T and 40 kJ/m^3 higher than that by vacuum sintering,respectively. The SEM photos indicate that the microstructure of Ar-atmosphere sintered magnet is much more homogeneous,but vacuum sintered magnet is of many defects.

Ge nanoneedles were prepared by hydrothermal deposition process using Ge and GeO2 as the starting materials and copper sheet as the deposition substrate. The Ge nanoneedle sample was characterized by scanning electron microscopy （SEM）, energy dispersive X-ray spectrum （EDS）, transmission electron microscopy （TEM） and high-resolution transmission electron microscopy （HRTEM）. The results demonstrate that the sample is of typical needle structure and composed of monocrystalline Ge and amorphous Ge oxide outer layer,and its length is more than 10 μm. Furthermore, the formation and growth of the Ge nanoneedle are explained by the mechanisms of metal-catalyzed vapor-liquid-solid and oxide-assisted growth.

The effects of VC and Cr3C2 inhibitors against grain growth on the metallographical structure and mechanical property of ultrafine WC-8%Co cemented carbide were investigated systematically, and the two inhibitors were added separately or together. The results show that the hardness of WC-8%Co increases with the more dosage of inhibitors,but corresponding inhibitor composition point exists with the maximum bend strength and fracture toughness. WC-8%Co-0.2%VC-0.6 %Cr3C2 ,obtained by adding VC and Cr3C2 together,is of excellent comprehensive performance,and its HRA hardness is 92.9 ,bend strength σbb 4 370 MPa and fracture toughness KIC 9.1 MN^3.2.

The flow stress behavior of TA15 titanium alloy during hot compression was studied by-thermal/ mechanical model experiments. The results show that controlled by both strain rate and deforming temperature, the flow stress of the alloy decreases with deforming temperature increasing but increases with strain rate increasing. Based on experimental data,the constant in-the constitutive function of alloy hot plasticity was calculated. And the flow stress behavior is represented by a Zener-Hollomon parameter in a hyperbolic sine relationship.

The crystallization kinetics of the Zr based was investigated by differential scanning calorimetry amorphous alloys （Zr60 Al15 Ni25 and Zr65 Al10 Ni10 Cu15 ） （DSC） under nonisothermal conditions. The results show that the characteristic temperatures （Tg, Tx and Tp） of Zr60 Al15 Ni25 and Zr65 Al10 Ni10 Cu15- shift to higher ones with the increase of heating rate,and the supercooled liquid region is widened. Therefore, both the glass transition-and crystallization of Zr60Al15Ni25-and Zr65 Al10 Ni10Cu15-have kinetic effects. The activation energy of the two amorphous alloys was evaluated using Kissinger and Ozawa equations, and the resuls from the different equations are nearly equal. It can be seen from the data of activation energy,the thermal stability of the two alloys is high,and the glass transition-and initial crystallization of Zr65 Al10 Ni10Cu15-are more difficult than-those of Zr60 Al15 Ni25. However,once the crystallization starts, Zr65 Al10 Ni10Cu15-is more easier to crystallize.

According to the theory of meso-structure design and using the process of high-pressure granulation and subsequent low-pressure infiltration, Al particulate-toughened SiCP-Al/Al composite are prepared, where the volume fraction of SiC in the SiCP-Al agglomerate is 62% but 55% in the whole composite. Then its mechanical properties such as hardness, strength and toughness are studied. The results show that compared with 55% SiCP/Al common composite, the fracture toughness of SiCP-Al/Al composite increases slightly and the hardness increases by 50 % ;compared with 62 % SiCP/Al common composite, the fracture toughness improves by 33.7%.

The basic flow of rare earth recovery from iron alloy scraps is introduced. The purity of both Nd2O3 and Dy2O3 prepared by solvent extraction is more than 99% ,their non-rare earth impurity content accords with national standard, and the total recovery of rare earth is beyond 92%. Furthermore, this process is quite stable.

The long-distance positive pressure pneumatic conveying system of volatilization kiln dust in a certain plant is systemically introduced from its project selection, design ideas, equipment selection and use. The correlative characteristics and design approach of the system are also analyzed.

The contents of W and Mo in Nb-W-Mo alloy were determined by X-ray fluorescence spectrometer with the optimal measurement condition combination. Based on the corresponding relation between absolute fluorescence intensity and elementary mass fraction, the correction equations were chosen to fit the actual working curves of W and Mo in Nb-W-Mo alloy. The results show that both the precision and accuracy of X-ray fluorescence spectrometry are high enough to compare with national standard chemical test or ICP test.