The methods of dealing with some key problems in analyzing a rotary forging process with a finite element method are given. The presented mechanical model of the finite element analysis is in accordance with the actual conditions of the rotary forging process. A three-dimensional rigid–plastic finite element analysis code is developed in FORTRAN language and used to analyze the rotary forging process of a ring workpiece. Velocity fields and stress-strain fields of both contact and non-contact zones of the ring workpiece in the rotary forging are obtained. The deformation mechanism and metal flow laws of the contact zone surface of the ring workpiece in the rotary forging process are revealed. The pressure distributions of the contact surface along the radial and tangential directions and effects of rotary forging parameters on deformation characteristics are given.

A new cold precision forging technique is proposed to form a spur gear from a hollow billet, that is blocking the divided flow region and then final forging by the relief hole. 3D2FEM simulation of the whole process of a pure alu-minium spur gear is performed using DEFORM-3DTM. The load-stroke curve, effective stress distribution, effective strain distribution, velocity distribution, and so on, are achieved. These results are compared with those achieved using the conventional closed die forging in the same conditions. The results show that this new technique has many advantages over the conventional one. The deformation load is reduced by near 30% and the filling ability of the tooth profile is also improved. Precision forging experiments of spur gears with the new process were performed using material Pb. The experimental results show a good agreement with the numerical results.

In recent years, rapid prototyping(RP) and rapid tooling(RT) technologies have been implemented in many aspects of industry, especially in the area of new product development. Based on RP and RT technologies, a rapid design and manufacturing system of the product was proposed in this paper. From two ways of a concept or a sample to the final product design, a reverse engineering technology, transmission processing software or modules of the input data, structure analysis and optimization means and manufacturing process analysis tools were integrated in the system. Some examples of applications show that the integrated system not only can reduce the numbers of design iterations but also improve the efficiency and reliability of the product design.

与精锻成形工艺相比，传统的切削加工方法加工直齿轮具有诸多弊端，而当前提出的闭式镦挤成形工艺载荷过大，严重制约着精密成形直齿轮工艺的实用化。本文提出采用预锻分流区—分流终锻新工艺精密成形直齿圆柱齿轮，设计了能够进行多种组合的精锻成形实验模具，并对空心管坯和实心圆柱坯进行了传统的闭式镦挤和新的分流成形工艺实验，实验结果表明：与传统的闭式镦挤和现有的圆柱直齿轮成形工艺对比，本文提出的成形工艺工序简单，终锻后齿形充填饱满，端面平整，而且成形载荷降低了37%以上，具有生产实用化的前景。

介绍了金属塑性成形过程中微观组织演变的数学模型和常用的微观组织优化目标函数，给出了金属塑性成形微观组织模拟和优化的主要方法——微观遗传算法和灵敏度分析方法的基本原理，叙述了近年来国内外金属塑性成形微观组织模拟与优化研究概况。