烧结?Al?B4C 复合材料的往复滑动磨损性能

采用粉末冶金法制备了不同 B₄C 含量（1wt%、6wt%、15wt% 和 30wt%）的碳化硼增强铝基复合材料（Al?B₄C）,并研究了 B4C 含量对其力学性能和摩擦学行为的影响。在7 N载荷下, Al?30B₄C 复合材料的密度最高 (~2.54 g/cm3)、孔隙率最低 (4%)、维氏硬度最高 (HV ~75)、重量损失最低 (0.4 mg) 和比磨损率最低 (0.00042 mm3/ (N·m)),与纯铝相比,硬度提高167%,失重降低75.8%,比磨损率降低76.7%。此外,磨损表面的扫描电镜图像显示,Al?B₄C复合材料在7 N载荷下的最窄磨损槽为0.85 mm,主要磨损机制为磨粒磨损机制。根据摩擦分析,表面之间的摩擦系数随着碳化硼含量的增加和外加载荷的减少而增加。总之,就 Al?B₄C 复合材料的摩擦学和力学性能而言,B₄C 是一种有效的增强材料。     

Processing and characterization of the microstructure and mechanical properties of Al6061–TiB2 composite

In the present research, aluminum metal matrix composites were processed by the stir casting technique. The effects of TiB2 rein-forcement particles, severe plastic deformation through accumulative roll bonding (ARB), and aging treatment on the microstructural charac-teristics and mechanical properties were also evaluated. Uniaxial tensile tests and microhardness measurements were conducted, and the micro-structural characteristics were investigated. Notably, the important problems associated with cast samples, including nonuniformity of the rein-forcement particles and high porosity content, were solved through the ARB process. At the initial stage, particle-free zones, as well as particle clusters, were observed on the microstructure of the composite. However, after the ARB process, fracturing phenomena occurred in brittle ceramic particles, followed by breaking down of the fragments into fine particles as the number of rolling cycles increased. Subsequently, com-posites with a uniform distribution of particles were produced. Moreover, the tensile strength and microhardness of the ARB-processed com-posites increased with the increase in the reinforcement mass fraction. However, their ductility exhibited a different trend. With post-deforma-tion aging treatment (T6), the mechanical properties of composites were improved because of the formation of fine Mg2Si precipitates.     

原位生成NbC增强YCF102熔覆层热力学与耐磨性研究

熔覆层性能难以满足特定的工艺要求,已成为限制激光熔覆发展的关键因素之一.鉴于此,在45号钢基体上制备出原位生成NbC增强YCF102熔覆层,并进行了热力学分析.通过XRD,SEM和EDS对其微观形貌及组成成分进行了分析,对其显微硬度及耐磨性进行了研究.结果表明:激光功率的改变对激光熔覆过程中原位反应的反应程度有显著影响,过大或者过小的激光功率均会对原位反应的发生起到抑制作用;YCF102熔覆层中原位生成的NbC颗粒的主要形态为四边形和花瓣形;当激光功率为525W时,原位生成NbC增强YCF102熔覆层具有较高的显微硬度及良好的耐磨性.     

羰基铁吸波材料性能提升研究进展

为了研究提升羰基铁吸波材料吸波性能,对大量研究羰基铁吸收剂的形貌控制、表面包覆材料以及与其他不同损耗吸收剂复配的文献进展进行回顾和概括,并对今后羰基铁性能提升方面的研究走向进行展望.研究结果表明,羰基铁吸收剂仍将是今后隐身和电磁兼容领域研究和应用的主要方向.     

灰铸铁孕育技术及其机理

本文就目前国内外的常用孕育剂、孕育方法、孕育机理进行了全面介绍.     

The synergistic effect of quaternary ammonium cations on the corrosion inhibition of Fe by inorganic anions

The synergistic effect of tetrabutylammonium cation (TBA⁺) or N-hexadecylpyridinium cation (HDP⁺) and SCN⁻ or I⁻ in 0.5 mol·L⁻¹ H₂SO₄ solution on the corrosion inhibition of Armco iron was investigated by potentiodynamic polarization and polarization resistance measurements. The results show that the synergistic effect of HDP⁺ containing π-electron and anion is stronger than that of TBA⁺ and anion. The joint adsorption models of cation and anion at electrode-solution interface are related to the structure and property of both ions by analyzing the desorption behaviours of both ions when the electrode is polarized anodically. Supported by the national scientific foundation of China Zou Jinyun: born in Aug. 1936. Prof.     

陶瓷等静压成型高分子模具材料研究

合成了聚氨酯弹性体(PUR)用的A料和B料.并用所研制的原料合成了PUR材料.原料和材料的性能均达到了国外先进水平。     

Fe_3Al合金形变诱导有序显微结构及合金元素的作用(Ⅱ)

从变诱导有序显微结构变化的角度，说明了合金元素铬和钼对Fe3Al基合金力学性能和显微组织的影响．结果表明：合金元素铬和钼主要固溶于Fe3Al基合金中，铬的主要作用是固溶软化，促进形变诱导无序化；钼主要起因溶强化作用，阻碍形变诱导无序化，有利于蠕变回复诱导有序化．