Microstructure and properties of Al-0.70Fe-0.24Cu alloy conductor prepared by horizontal continuous casting and subsequent continuous extrusion forming

A novel process for manufacturing A1-0.70Fe-0.24Cu alloy conductor was proposed, which includes horizontal continuous casting and subsequent continuous extrusion forming （Conform）. The mechanical properties, electrical conductivity and the compressed creep behaviour of the alloy were studied. The results indicate that the Conform process induces obvious grain refinement, strain-induced precipitation of AI7CuzFe phase and the transformation of crystal orientation distribution. The processed alloy has good comprehensive mechanical properties and electrical conductivity. Moreover, a better creep resistance under the conditions of 90 ~C and 76 MPa is shown compared with pure A1 and annealed copper, and the relationship between primary creep strain and time may comply with the logarithmic law. The enhanced properties are attributed to the grain refinement as well as the fine and homogeneously distributed thermally stable A1Fe and A17Cu2Fe precipitation phases.

Microstructural Characteristics and Wear Performance of Plasma Sprayed Al_2O_3-13 wt. % TiO_2 Coating on the Surface of Extrusion Wheel

The conventional Al2O3-13 wt. % TiO2 composite ceramic coatings are fabricated by plasma spraying on the surface of extrusion wheel. The microstrueture, morphology and phase compositions of the substrate and coat- ing are investigated by using X-ray diffractometry （XRD） , scanning electron microsopy （SEM） and energy dis- persive spectroscopy （EDS）. Moreover, the microhardness of the substrate and the coating are investigated using Vickers mierohardness tester, the friction and wear behaviors of the substrate and the coating are investigated by using a block-on-ring tribometer under dry sliding conditions with the load of 245 N. The results show that both γ-Al2O3 and α-Al2O3 phases are observed in the as-sprayed coatings, the mian phase is γ-Al2O3. There are white particulates Al2O3 on its surface. The Al2O3-13 wt. % TiO2 coating possesses higher mierohardness which is about 1018HV and 1.6 times that of the substrate. The wear performance of coating is better than that of the substrate. In a practical application, the life of the extrusion wheel which is plasma sprayed Al2O3-13 wt. % TiO2 coating on the surface is 1.2 times that of the conventional extrusion wheel, and the life is about 330 h.

Microstructures and mechanical properties of AZ31-0.1Ca magnesium alloy produced by soft-contact electromagnetic casting and hot extrusion

An AZ31-0.1Ca magnesium alloy produced by Soft-contact electromagnetic continuous casting （SEMC） was investigated. The fine homogeneous structure and the precipitated phases were obtained by SEMC. The effects of microalloying of Ca and middle frequency electromagnetic field on AZ31-0.1Ca magnesium alloy were discussed. And the as-cast billets were extruded with different extrusion ratios subsequently. The alloy showed an ultrafine grain size of 2-5 #m due to dynamic recrytallization （DRX） in the course of hot extrusion. The comprehensive properties of the as-extruded alloy are the best at the extrusion ratio of 25, and the hardness, UTS and elongation are 73.9 HB, 356.8 MPa and 16.570, respectively.

盐酸文拉法辛缓释胶囊制备

目的研究盐酸文拉法辛缓释胶囊的制备工艺和处方。方法首先用挤出滚圆造粒机制备盐酸文拉法辛微丸,微丸包衣,装胶囊,通过评价微丸的特征、收率和胶囊体外释放度,筛选最佳处方和工艺。结果用挤出滚圆法制备的盐酸文拉法辛微丸圆整度好,收率高。经包衣、填装胶囊制备的盐酸文拉法辛缓释胶囊的释放度与进口盐酸文拉法辛胶囊一致。结论挤出滚圆法制备盐酸文拉法辛微丸工艺简便易行,制得的微丸质量好,收率高;用乙基纤维素包衣获得满意的释放度。