AZ91D合金的挤压铸造工艺及性能

采用直接挤压铸造成形工艺,研究了挤压铸造工艺参数和热处理对AZ91D合金力学性能的影响.研究结果表明:①在浇注温度、挤压压力和保压时间三个工艺参数中,浇注温度对AZ91D合金的影响最大,其次是挤压压力,保压时间的影响最小;②固溶处理在提高AZ91D合金的抗拉强度和硬度的同时提高其延伸率,而固溶时效处理会提高合金的抗拉强度和硬度,但降低其延伸率.     

在冲裁凹模平面固定板上固定镶块的研究

本文对冲裁凹模进行了受力分析，得到了镶块固定的影响因素及力学关系， 以供设计参考.     

Data mining driven DMAIC framework for improving foundry quality – a case study

Six Sigma Define-Measure-Analyze-Improve-Control (DMAIC) methodology has been widely used across industries as the best systematic and data driven problem solving approach for quality improvement. Statistical Design of Experiment (DOE) is used in the ‘Improve’ stage for obtaining optimal process settings for significant variables contributing towards quality improvement. But, DOE is an offline activity requiring time and other resources for conducting experiments and analyses. Further, there are many small and medium scale enterprises that cannot afford to conduct DOE. Under such practical constraints, it is desirable to apply DMAIC using online process data under day-to-day production situations or with little changes in process settings without compromising production. In this article, we propose a DMAIC framework, driven by data mining techniques for defect diagnosis and quality improvement where historical and online process data can be effectively utilised. We have used two decision tree algorithms namely, Classification and Regression Tree and Chi-squared Automatic Interaction Detection in developing the proposed framework. The proposed approach is applied in an Indian grey iron foundry where conducting DOE is not a feasible option for the management. The result demonstrates a significant reduction in casting defect and validates the practical viability of this approach.     

货车侧架薄壁铸钢件凝固的数值模拟

在微机上对货车侧架大型薄壁铸钢件凝固进行数值模拟,通过充型过程温度场模拟解决初始条件,计算出气隙值。计算部位模拟结果与实际相符。说明本文提供的具有图形功能的软件是实用的。     

AZ31B镁合金复合陶瓷涂层在SBF溶液中的应力腐蚀研究

为了研究微弧氧化一电泳沉积复合陶瓷涂层对镁合金在模拟体液( SBF)中的应力腐蚀行为的影响程度,采用微 弧氧化一电泳沉积的复合处理方法在A23IB镁合金表面制备复合陶瓷涂层,使用电化学实验和慢应变速率拉伸试验研究 有无复合陶瓷涂层在SBF溶液中的腐蚀和应力腐蚀行为。研究结果表明：复合陶瓷涂层能提高A23IB镁合金在SBF溶 液的耐蚀性能,但是对A23IB镁合金在SBF溶液中的应力腐蚀敏感性影响甚微。     

Implementation of holonic scheduling and control in flow-line manufacturing systems: die-casting case study

The success of a flow-line manufacturing system depends on effective production scheduling and control. However, it has been found that current flow-line manufacturing scheduling and control algorithms lack the flexibility to handle interruptions or resource breakdowns; hence, system performance drops automatically and rapidly when interruptions occur. The objective of this research is to investigate if the performance of a flow-line manufacturing system can be improved by integrating agent-based, holonic scheduling and production control. A holonic manufacturing scheduling model has been developed and implemented into a die-casting manufacturing flow line throughout a simulation model. The analysis takes into account the comparisons of overall performances of the system models with the holonic scheduling and conventional scheduling approaches. Simulation results indicate that the holonic manufacturing scheduling and control can significantly increase the uptime efficiency and the production rate of the flow-line manufacturing system.     

A possibilistic aggregate production planning model for brass casting industry

This article discusses a possibilistic aggregate production planning (APP) model for blending problem in a brass factory; the problem computing optimal amounts of raw materials for the total production of several types of brass in a planning period. The model basically has a multi-blend model formulation in which demand quantities, percentages of the ingredient in some raw materials, cost coefficients, minimum and maximum procurement amounts are all imprecise and have triangular possibility distributions. A mathematical model and a solution algorithm are proposed for solving this model. In the proposed model, the Lai and Hwang's fuzzy ranking concept is relaxed by using ‘Either-or’ constraints. An application of the brass casting APP model to a brass factory demonstrates that the proposed model successfully solves the multi-blend problem for brass casting and determines the optimal raw material purchasing policies.     

竹叶状硼酸镁纳米材料的制备与表征

以Mg（NO3）2·6H2O和Na2B4O7·10H2O为原料,采用水热法制备了竹叶状的硼酸镁纳米材料,用扫描电子显微镜和透射电子显微镜观察了产物的形貌,用电子散射能谱分析仪和x射线粉末衍射仪对产物的成分以及物相进行了表征．结果表明产物几乎全是竹叶状纳米结构,纯度与产量均较高,形貌和尺寸比较均匀,成分为单斜晶系的MgBO,（OH）．     

„Coaching“ durch die Führungskraft — eine kritische Betrachtung

?Leadership Coaching“ — A critical discussion?Leadership Coaching“ comes into vogue again. It is possible that cutting down the expenses for HRM (and specially for counsultants) reinforces this trend. Therefore it is again time to discuss the question about the main differences between “leadership coaching” and coaching by professionals. Consultations by the superior can be helpful, however there are distinct differences to the professional coaching.