薄膜传动带拉制成形工艺研究

结合加工技术实践,对薄膜传动带的拉制原理、加工方法、试验和检测、制造和应用中出现的一些明显纵向弯曲、骤断、试验和使用时发生的脱带、断带现象,进行了简要介绍和初步讨论,解决小型精密机械的传动问题。     

无切口连续拉深成形工艺分析及模具设计要点

阐述了无切口连续拉深成形的工艺分析思路和模具设计要点，并对实际生产中出现的问题进行了剖析，给出了解决问题的办法。     

A toolpath strategy for improving geometric accuracy in double-sided incremental sheet forming

The double-sided incremental forming (DSIF) improved the process flexibility compared to other incremental sheet forming (ISF) processes. Despite the flexible nature, it faces the challenge of low geometric precision like ISF variants. In this work, two strategies are used to overcome this. First, a novel method is employed to determine the optimal support tool location for improving geometric precision. In this method, the toolpath oriented the tools to each other systematically in the circumferential direction. Besides, it squeezed the sheet by the same amount at the point of interest. The impacts of various support tool positions in the circumferential direction are evaluated for geometric precision. The results demonstrate that the support tool should support the master tool within 10° to its local normal in the circumferential direction to improve the geometric accuracy. Second, a two-stage process reduced the geometric error of the part by incrementally accommodating the springback error by artificially increasing the step size for the second stage. With the optimal support tool position and two-stage DSIF, the geometric precision of the part has improved significantly. The proposed method is compared to the best DSIF toolpath strategies for geometric accuracy, surface roughness, forming time, and sheet thickness fluctuations using grey relational analysis (GRA). It outperforms the other toolpath strategies including single-stage DSIF, accumulative double-sided incremental forming (ADSIF), and two-stage mixed double sided incremental forming (MDSIF). Our approach can improve geometric precision in complex parts by successfully employing the support tool and managing the springback incrementally.     

高超声速飞行器控制面热防护技术跟踪研究

简要介绍了高超声速飞行器控制面的气动热环境特点,在此基础上,从热管理的角度对各种类型的热防护方案分别进行分析,论证了高超声速飞行器控制面采用热结构方案的合理性;并对高超声速飞行器控制面热结构方案的特点和进展、改进热结构的途径进行了综述和分析。     

高温TiAl合金热成形技术研究进展

γ-TiAl合金具有优异的高温性能,是航空发动机650~900℃服役温度区间的重要候选材料。在回顾TiAl合金发展过程与应用现状的基础上,主要介绍了TiAl合金铸锭熔炼、铸造、包套等温锻造、包套热挤压等热加工技术的研究进展,提出了TiAl合金低成本近净成形技术面临的机遇和挑战。     

热塑性成形过程微观组织模拟研究新进展

金属在热塑性成形过程中微观组织发生晶粒形核、长大、相变、再结晶等一系列的复杂变化,直接影响加工过程与产品的机械性能。本文对目前应用在热成形微观组织演变模拟方面的主要模拟技术作了比较全面的评述,对比了不同微观组织模拟方法,总结了利用各种模拟技术所取得的最新研究成果。     

2D-Cf/SiC复合材料及构件的无压成型工艺

采用无压成型工艺制备了2D-Cf/SiC及复杂构件。结果表明:复合材料弯曲强度达到328MPa,断裂韧度达到14.9MPa·m1/2,层间剪切强度达到35.9MPa,同时材料也具有很好的高温抗氧化性能。利用本工艺制备了某型号发动机的尾喷管,并成功通过了应用部门的试车考核。     

TC_4钛合金超塑成形/扩散连接组合工艺应用研究

 TC4（Ti-6Al-4V）钛合金板材超塑成形/扩散连接（SPF/DB）组合工艺的可行性和对影响钛板SPF、SPF/DB的主要工艺因素。着重阐述某机框段和舱门的研制情况,提供了合理的工艺参数和流程。     

大厚度Ni_(75)B_(17)Si_8非晶合金的制备

 研究了净化Ni_(75)B_(17)Si_(8)合金液的方法以及净化对非晶形成能力的影响,通过净化工艺消除合金液内的异质质点可提高合金液的非晶形成能力;釆用净化和急冷相结合的工艺制备出了20×10×0.5(mm~3)的Ni-(75)B_(17)Si_(8)非晶合金试样。     

体积成形过程的模型跟随自适应控制

为控制热锻的生产过程和锻件的产品质量 ,应用体积成形过程的有限元数值仿真离线训练人工神经网络 (ANN) ,采用电学模拟方法 ,通过简单的模拟电路构造出复杂的ANN模型 ,完成了从体积成形过程到模拟电路之间的映射。模拟电路与自适应控制系统并联 ,构成了模型跟踪的自适应控制系统