改性硅微粉填料对铁硅铝磁粉心性能的影响

采用绝缘包覆的铁硅铝磁粉为原料、Zn(H2PO4)2·2H2O预处理的硅微粉为填料,制备270026(外径为270 mm,磁导率为26)型铁硅铝磁粉心,研究Zn(H2PO4)2·2H2O处理量对铁硅铝磁粉心磁学性能和抗折强度的影响。结果表明:当Zn(H2PO4)2·2H2O用量为硅微粉质量的15%,频率在1~1 000 k Hz范围内,制备的磁粉心磁导率约为24.8;频率为100 kHz时,外加100 Oe直流磁场,磁粉心直流叠加百分比接近85%;频率为200 kHz时,磁粉心品质因素Q值达到141;频率为50 kHz、磁粉心磁通密度100 mT时,磁粉心的磁损耗低于175 m W/cm3;此外,磁粉心的抗折强度达到19.7 kPa。制得的270026型铁硅铝磁粉心样品,其磁学性能和抗折强度都优异于常规商用的270026型铁硅铝磁粉心产品。

Fractal Calculation of Mo／β‘—Sialon Functionally Gradient Materials by Powder Metalurgy

The preparation of disk shaped Mo/β'-sialon functionally gradient material(FGM) is studied.Random fractal of diffusion interface in Mo/β'－sialon FGM is also studied by variation method.

Prediction on the viscosity of multi-component melts with a new geometric model

A geometric model for calculating the viscosity of multi-component melt fromrelated binary physicochemistry properties was derived based on Chou's thermodynamic geometricmodel. The model derived was employed to predict the viscosity of Au-Ag-Cu alloys. The results showthat the calculated viscosity for Au-Ag-Cu alloys meet the experimental data very well. In addition,the viscosity of Bi-Sn-In systems was also predicted with this model.

Carbonthermal Reduction—Nitridation Method for Preparation of O‘—Sialon—SiC—ZrO Composites

Based on thermodynamic analysis,O'-Sialon-SiC-ZrO2 composites have been prepared by carbonthermal reduction-nitriation from natural kaolin and zircon with certain additives,The modulus of racture of well sintered specimen may reach 110 MPa,The process of reaction-sintering has been discussed,The formation temperature of O'-Sialon is 1718 K by calcuation.

Development of ZrO2—CaO—BN Composite

The weaknesses of submerged nozzles being used now were analyzed and ZrO2-CaO-BN composite was proposed to develop to overcome them.The feasibility to prepare ZrO2-CaO-BN compostie was made by thermodynamic method and the omposite was prepared in hot-press.The phase components of the composite were identified by X-ray diffraction method(XRD) and the microstructure of the composite was observed with SEM. Th results were consistent with thermodynamic calculation.

Application of protonic conductors in metallurgy

Two types of disposable EMF hydrogen sensors for measurements ofsolute contents of liquid metals in situ in metal-refining processesand their general principles are introduced. The way to design newelectrochemical sensors and the direction to develop new protonicconductors as new electrochemical sensors are discussed. Thefeasibility of protonic conductors worked as hydrogen pump innon-ferrous metal refining processes is discussed as well.

Estimation of Gibbs Free Energy of Formation of Sialon （O‘—and X—Phases

Based on introducing the quasi-parabolid rule,which indicates the relation of Gibbs free energy of formation of compounds and its compostitions,the Gibbs free energes of formation of Sialons (O'-and X-phases) were estimated.

Thermodynamic Investigation of Synthesizaing Metastable β—Sialon—Alon Composite Ceramic

Based on its thermodynamic analysis ,β-Sialon-Alon metastable composite ceramic has been prepared by hot pressing sintering,XRD results indicate that the product of hot pressing singering is indeed Sialon-Alon metastable omposite ceramic ,which is in accordance with thermodynamic