基于PRO/E的十字头铸件工艺设计及数值模拟

对十字头铸件的零件结构及使用要求进行工艺分析,采用pro/E软件对十字头铸件进行三维建模、工艺设计、生成模具模型,运用CAE软件对铸件充型过程和凝固过程进行数值模拟;分析了成型铸件产生缺陷的位置及原因,并在此基础上优化铸造工艺,对缩短生产试制周期,降低生产成本具有重要意义.     

金属基复合材料及其发展现状

综述了当前国内外金属基复合材料的发展现状、性能特点、应用及制备方法。     

试论铸造锌基复合材料的常温及高温性能

从材料的强度、硬度、韧性等方面叙述了铸造锌基复合材料的常温及高温下工作的特点。分析表明 ,铸造锌基复合材料不仅在常温下具有较高的强度及硬度 ,在高温下也具有优越的性能。     

稀土Gd对Zn-25Al-2.5Si组织及力学性能的影响

研究了不同含量的稀土Gd对Zn-25Al-2.5Si合金的显微组织和力学性能的影响。结果表明,Gd元素能够起到明显的晶粒细化作用;Gd能提高合金的室温和高温力学性能。合金的室温拉伸强度、显微硬度有所提高,高温强度和硬度提高明显。180℃时的抗拉强度比不加Gd时提高45.6%,硬度提高78.2%。分析其原因是晶粒细化和Gd本身的性质起了主要作用。     

Microstructure and Properties of SiC/Gr Composite Reinforced Aluminum Matrix Composites Material

SiC/Gr/ZL101 aluminum-based composites were prepared by semi-solid stirring and gravity pouring method. The effects of SiC/Gr with different volume fractions on the microstructure and property of aluminum-based composites were studied by means of microstructure observation, tensile test, fracture scanning analysis and damping capacity test. The results show that the primary phase α-Al of ZL101 alloy prepared by semi-solid stirring and gravity pouring method is fragmented dendrite, along with the rising SiC volume fractions, the tensile strength of the composites first increases and then decreases while its elongation gradually decreases, the maximum tensile strength of the material can reach 168 MPa, up to 16% than that of ZL101 alloy, the fracture morphology is obviously brittle fracture. They also show that the addition of SiC and Gr improves the damping capacity of ZL101 alloy, the internal dissipation Q~(-1) of the composites is obviously higher than that of matrix alloy and gradually increases along with the rising SiC volume fractions. The damping mechanism of the composites is mainly the combined effects of both dislocation damping and interfacial damping.     

Effect of heat-treatment on the microstructures and mechanical properties of Mg-10Zn-5Al-0.1Sb-xCu magnesium alloy

The effects of the solution and aging treatment on microstructures and mechanical properties of the Mg-10Zn-5Al-0.1Sb-XCu cast magnesium alloys were investigated by brinell hardness measurement, scanning electron microscopy (SEM), energy spectrum analyzing apparatus and X-ray diffraction (XRD). The experimental results show that the strip-like τ-Mg₃₂ (Al, Zn)₄₉ phase is shown at the grain boundaries and Mg₂Cu phase become smaller, even granular after solution treatment at 350 °C for 24 h. By ageing treatment at 180 °C, the ternary strengthening phase (τ phase) precipitates gradually at or around grain boundary. With increasing aging time, the micro-hardness improves obviously and up to the maximum (105.9 HV) at aging time of 36 h. In addition, the tensile-strengths at room temperature and at an elevated temperature respectively reach 228 MPa and 176 MPa, which is increased by 20% and 10%, respectively.     

低过热度浇注SiC_p/Gr/ZL101复合材料组织与性能研究

采用半固态搅拌、低过热度重力浇注的方法制备了SiCp/Gr颗粒复合增强ZL101铝基复合材料。通过显微组织观察、拉伸试验以及阻尼性能测试,研究了不同体积分数SiCp/Gr对铝基复合材料性能的影响。结果表明,通过半固态搅拌、低过热度重力铸造法,使ZL101合金中的初生相α-Al由枝晶形态变为蔷薇状,晶粒明显细化。随着SiCp体积分数的增加,复合材料的抗拉强度先升高后降低,伸长率逐渐下降,复合材料的最高抗拉强度达到191MPa,比ZL101合金提高了32%。SiCp与Gr的加入改善了ZL101合金的阻尼性能,复合材料的内耗值Q-1明显高于基体合金,并且随着SiCp体积分数的增加,复合材料内耗值Q-1逐渐提高。     

固溶时效对半固态挤压SiC/AZ91D组织与性能的影响

为了获得综合力学性能良好的镁基复合材料,采用近液相线保温法制备10μm 15%SiC/AZ91D(质量分数)半固态坯料进行半固态挤压后得到其复合材料,再经过415℃固溶处理24 h(T4)和进一步220℃时效处理8 h(T6)。结果表明:随着固溶时效的进行,晶界处的层片状和点状Mg₁₇Al₁₂相溶解,然后在晶粒中二次析出,并逐渐球化。与T6处理前的15%SiC/AZ91D复合材料相比,经T6处理后其具有良好的综合力学性能,拉伸强度、屈服强度、伸长率和硬度(HV)分别达到242 MPa、204 MPa、2.3%和1322 MPa。     

材料阻尼及ZA合金阻尼性能的研究现状

综述材料的阻尼特性及ZA合金阻尼性能的机制测量方法与研究现状。