高性能铝基复合材料的设计与加工技术

从铝基复合材料微观结构特征与性能关系角度,回顾了承载结构用典型铝基复合材料在体系设计、制备与成型加工研究方面的成果与进展,同时简要介绍了近期铝基复合材料为实现性能突破所开展的研究探索,最后根据铝基复合材料的发展历程与现有研究的特点对铝基复合材料今后的研究应用进行了展望。     

颗粒增强铝基复合材料的研究与应用

介绍了颗粒增强钒基复合材料的性能特点,铝基复合材料基体与增强体润湿性的研究现状.总结了铝基复合材料的应用情况以及国内外的研究现状.     

铸造铝基复合材料研究的进展

综述了铸造铝基复合材料的研究和进展。阐述了几种制备铝基复合材料的新兴铸造工艺技术，包括旋涡搅拌铸造法、压力铸造法、喷射铸造法、熔铸直接接触反应法等工艺技术。简介了铸造铝基复合材料在国内的发展概况。在比较几种铸造铝基复合材料工艺技术特点与性能的基础上，对有关研究趋势进行了分析与讨论。     

铝基复合材料的制备及应用

介绍了常见铝基复合材料的类型,阐述了铝基复合材料的制备工艺及应用,总结了我国目前铝基复合材料的研究状况及其发展趋势.     

石墨烯增强铝基复合材料研究现状及其界面问题热力学分析

由于石墨烯具有独特的二维结构和优异的力学、热学、电学性能,近年来受到广泛的关注。因此,石墨烯被作为增强体应用于铝基复合材料。综述了近几年石墨烯/铝基复合材料的主要研究方向和进展、制备方法与工艺、石墨烯增强机理等;讨论了石墨烯/铝基复合材料制备过程中的界面反应、Al_3Mg_2和Si C与脆性相Al_4C_3反应生成的竞争机制、石墨烯在铝基体中分散等问题;展望了石墨烯增强铝基复合材料的发展方向,为新型石墨烯/铝基复合材料的研究和应用提供参考。     

铝基复合材料凝固与成形一体化技术

针对铝基复合材料塑性成形困难、增强相与基体金属界面相容性差的问题,提出铝基复合材料凝固与成形一体化技术,实现了铝基复合材料管材、线材和型材的连续近终形成形,并改善粒子相与铝界面相容性和强化作用,达到短流程,低能耗成形的目的.研究了铝基复合材料连续凝固与成形过程的组织演化规律和制品性能,优化了凝固成形条件.     

碳化硅颗粒增强铝基复合材料的研究现状及发展趋势

综述了铝基复合材料的发展历史及国内外研究现状,重点阐述了碳化硅颗粒增强铝基复合材料制备工艺的发展现状.同时说明了碳化硅颗粒增强铝基复合材料研究中仍存在的问题,在此基础上展望了该复合材料的发展前景.     

颗粒增强铝基复合材料热变形行为研究进展

从颗粒增强铝基复合材料流变应力行为、热变形过程中显微组织的变化以及热加工图三个方面,对颗粒增强铝基复合材料的热变形行为进行了概括。同时介绍近年来国内外研究人员针对颗粒增强铝基复合材料热变形方面所展开的探索和研究,最后对颗粒增强铝基复合材料今后的研究应用进行了展望。     

铸造铝基复合材料的研究进展

铸造法是铝基复合材料制备方法中最经济的方法之一。本文概述了低压铸造、挤压铸造和搅拌铸造三种制备铝基复合材料的方法及特点。简介了上述制备铸造铝基复合材料方法在国内外的研究现状。探讨了铸造铝基复合材料的发展方向。     

碳化硅颗粒增强镁基复合材料损伤性能的研究

本文研究了碳化硅颗粒增强镁基复合材料的损伤性能，并与铝基复合材料的损伤性能进行对比。结果表明，碳化硅颗粒增强镁基复合材料损伤曲线分为三个阶段，初始损伤阶段（高速率线性阶段）；损伤延迟阶段（低速率平缓阶段）；损伤加速阶段。与纯铝基复合材料和7075铝基复合材料相比，碳化硅颗粒增强镁基复合材料损伤曲线的损伤延迟阶段非常平直，因此抗损伤性能优于铝基复合材料。对颗粒增强复合材料来说，强结合界面对提高材料损伤抗力的作用要优于弱结合界面。     

汽车后桥车间物流系统分析及其方案优化

针对汽车后桥车间生产物流系统建立petri网模型,分析了petri网的可达性,研究了零部件加工、装配工艺流程和物流系统通畅性,采用了不同的算法,对生产物流的两部分工序物流和工艺物流分别计算最小物流量距积和,得出局部和整体优化方案.     

基于流程衔接的物料信息编码的设计

物料信息编码是物料管理系统的核心,原材料、半成品和成品在物料管理系统运转的效果取决于信息编码的质量.研究了物料信息编码理论和实践,利用物料信息编码原则与其特征分类的原理设计了一个总体物料信息编码方案.针对原材料入库与发出的复杂性和生产中成品与半成品的流程衔接,分别为原材料、成品和半成品设计了可衔接的编码,使其成为一个统一的编码体系.     

Modeling of material flow in friction stir welding process

This paper presents a 3D numerical model to study the material flow in the friction stir welding process. Results indicate that the material in front of the pin moves upwards due to the extrusion of the pin, and then the upward material rotates with the pin. Behind the rotating tool, the material starts to move downwards and to deposit in the wake. This process is the real cause to make friction stir welding process continuing successfully. The tangent movement of the material takes the main contribution to the flow of the material in friction stir welding process. There exists a swirl on the advancing side and with the increase of the translational velocity the inverse flow of the material on the advancing side becomes faster. The shoulder can increase the velocity of material flow in both radial direction and tangent direction near the top surface. The variations of process parameters do have an effect on the velocity field near the pin, especially in the region in which the material flow is faster.     

Three-Dimensional Visualization of Material Flow During Friction Stir Welding of Steel and Aluminum

Material flow is a key phenomenon to obtain sound joints by friction stir welding (FSW), and it is highly dependent of the welded material. It is well known that the optimal FSW condition depends on the welded material. However, the material flow during FSW has not been totally clarified in spite of many researches. Especially, the material flow of steel during FSW is still unclear. It seems difficult to understand the material flow by the traditional method such as the tracer method or observation of the microstructure in the stir zone. Therefore, in this study, the material flow of steel was three dimensionally visualized by x-ray radiography using two pairs of x-ray transmission real-time imaging systems, and was then compared with the material flow of aluminum. The result revealed the effect of the welded material on the material flow during FSW.     

Effects of process parameters on material side flow during hard turning

The phenomenon of material side flow represents an important aspect of machined surface quality during hard turning. In this paper, an experimental study was performed to investigate the main features of this phenomenon. The effects of process parameters including edge preparation, nose radius, feed and tool wear on material side flow were examined. Two possible mechanisms for material side flow were investigated. In the first one, the material is squeezed between the tool flank face and the machined surface when chip thickness is less than a minimum value. In the second mechanism, the plastified material in the cutting zone flows through the worn trailing edge to the side of the tool. Both of these mechanisms can exist simultaneously. The results obtained from surface examination showed a strong correlation between edge preparation and material side flow. An increase in the tool nose radius resulted in a remarkable increase of material side flow. Feed had an indirect effect on material side flow. In addition, tool wear significantly affected the existence of material side flow on the machined surface. An increase in tool wear promoted the occurrence of material side flow.     

An evaluation of the statistics of steel material model parameters

In robustness studies, variations of material properties are often represented by simple assumptions, such as scaling of stress-strain relations, often due to lack of knowledge or deeper understanding of the material physics and the material model applied. By performing material characterisation tests on several batches of a DP600 steel and fitting a phenomenological material model to each batch, this paper studies the dispersion of material model parameters, as well as correlations between both experimental and model parameters. It is concluded that some of the characterisation tests may be omitted in the future, due to correlations found between parameters. The results may also be applied in a robustness study by inversely using the retrieved statistics to generate reasonable new sets of material model parameters. The methodology presented may be adopted for any other type of material characterisation process.     

热处理自动物料装备

自动物料装备对于防止混料、降低劳动强度、保证热处理品质和提高热处理自动化程度有重要的作用。本文介绍了物料输送设备、物料存储设备和物料布放收集设备等自动物料装备的特点、适用情况和实际应用效果,为广大热处理从业者在热处理工厂规划时提供帮助。     

钛合金曲面超声辅助磁性磨料光整加工材料去除规律及去除函数

目的研究工件曲率半径、驻留时间以及加工角度对钛合金曲面超声辅助磁性磨料光整加工材料去除深度和材料去除曲线偏置程度的影响,建立不同走刀方式下的材料去除函数。方法在不同工件曲率半径、驻留时间和加工角度下,对钛合金曲面工件进行单点抛光试验,利用方差分析法,研究各因素水平对材料去除深度及材料去除曲线偏置程度的影响规律,采用最小二乘法拟合材料去除点坑在xoz平面和yoz平面内的材料去除曲线,基于二次多项式逐步回归方法,构建不同加工工艺参数下,材料去除曲线函数系数与加工工艺参数间的函数表达式,建立不同走刀方式下的材料去除函数,并对其进行准确性检验。结果由材料去除深度方差分析可得:驻留时间的F值为8.06,加工角度的F值为2.296,材料去除深度随驻留时间和工件曲率半径的增加而增加,随加工角度的增大,先增加后减小。由材料去除曲线偏置程度方差分析可得:工件曲率半径的F值为2.176,加工角度的F值为7.647,材料去除曲线偏置程度随工件曲率半径的增大而减小,随驻留时间和加工角度的增加而增加。此外,拟合的材料去除函数相关系数值R^2在0.97~0.99范围内。结论驻留时间对材料去除深度的影响最显著,加工角度次之,工件曲率半径影响最小。加工角度对材料去除曲线的偏置程度影响最显著,工件曲率半径次之,驻留时间影响最小。材料去除函数拟合结果较为准确,能满足实际的加工要求。     

Drag material change in hot runner injection molding

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