用MSC．MARC实现大转矩三段弧鼓形齿联轴器应力分析研究

应用有限单元法及MSC．MARC有限元分析程序，对我公司设计生产的新型三段弧鼓形联轴器进行了分析研究，从应力分布及接触状态等方面探讨了这种新型联轴器的结构力学特性，得出了这种新型联轴器既保持了一般鼓形联轴器的挠性特点，又可增大外齿轴套与内齿圈齿间接触面积，有效减小其接触应力峰值的结论，为进一步推广应用这种新型联轴器提供了理论依据。     

Feasibility study of the ultrasonic vibration assisted drilling of Inconel superalloy

The ultrasonic vibration assisted drilling of Inconel 718 superalloy is studied in this paper. The tool holder of a machining center is retrofitted so that axial resonant vibration can be provided. Experimental results show that the chip size is reduced, and the variation of torque in drilling becomes smaller. These phenomena are particularly apparent at the final stage of a drill's usable life. It is also found that there is little improvement in drilling performance when the frequency of the ultrasonic vibration is varied. On the contrary, a drill's life is greatly increased when the vibration with a smaller amplitude is applied. But too large a vibration amplitude, such as over 12 μm in this study, could lead to negative effects. For the testing conditions, the frequency of 31.8 kHz and the amplitude of 4 μm result in the best drill life and quality of the drilled hole in this study. Under this condition a drill's life is prolonged by as much as 2.7 times of that without vibration assisted drilling process. Concerning drilling efficiency, it is found that by applying ultrasonic vibration assisted drilling, lifting of the drill for chip removal as commonly employed in conventional drilling of a high aspect ratio hole is not necessary, and saving of the working time is obtained.     

Computer Simulation of the Process of Quenching Large-Size Parts in Water and Aqueous Solutions

DESPITE of the rapid development of computerfacilities and numerical methods of computing thestress-strain state of large-size parts,the accuracy ofcomputations is not sufficient because of the lack ofaccurate input data.For this reason,heat treatingengineers do not trust computations and are afraid ofquenching of large-size parts in water,in particular,when Bi—>°°.There are some causes of suchsituation:1)Because of inaccurate boundary conditions andincomplete information on mechanical p…     

动态控制的低应力无变形焊接新技术

在成功地研究并开发了薄壁构件低应力无变形焊接新技术的基础上，把靠预置温度场静态控制焊接应力与变形的方法发展到动态控制法。这一新构思所形成的动态控制焊接应力与变形的新技术的原理在于：不再依赖预置温度场，而是直接利用电弧在薄壁构件上所形成的焊接温度，建立一个特殊构造的热潭跟随电弧，板成“热源－热潭“多源系统，在熔池后的高温焊缝区产生强烈的局部急冷拉伸作用，控制和补偿焊接时产生的压缩塑性变形，达到薄壁构     

氢致开裂和应力腐蚀机理的前沿问题

本文对各种氢致开裂和应力腐蚀机理进行了评述。指出,把氢促进局部塑性变形和弱键理论以及氢压理论联合起来就有可能发展新的氢致开裂机理;必须深入研究阳极溶解对位错发射,增殖和运动的影响才能提出合理的阳极溶解型应力腐蚀的机理。     

Effects of different metallurgical processing on microstructures and mechanical properties of inconel alloy 783

Different metallurgical processing, including the standard heat treatment, heat treatment without β aging, addition of high amount of Cr, and long-term isothermal exposure, was conducted on superalloy Inconel 783. For these processed materials, the tensile property and hardness at room temperature and stress relaxation behavior at 650 °C were examined. The testing results showed that isothermal exposure and heat treatment without β aging slightly enhanced the yield strength of alloy 783 at room temperature as well as all metallurgical processing in this study produced an identical stress relaxation behavior at 650 °C. The microstructure variation with different processing was analyzed using optical microscope, scanning electron microscopy (SEM), and transmission electron microscopy (TEM).     

缓蚀剂对316L不锈钢在酸性氯离子溶液中应力腐蚀开裂的作用

研究表明316L不锈钢在55℃的1mol/L HCl+1mol/L NaCl溶液中对SCC比较敏感。316L不锈钢在所研究的体系中处于活化溶解状态。对添加缓蚀剂的体系的电化学参数的测试和分析表明,缓蚀剂抑制SCC的能力与缓蚀剂抑制阳极反应有关。     

Effect of ultrasonic vibration on the dechromisation corrosion of a CuCr alloy in HCl solution

The effect of ultrasonic vibration on the dechromisation corrosion of a CuCr alloy in HC1 solution was studied and the corrosion mechanisms were analyzed. It is found that ultlasonic vibration reduces the dechromisation incubation time, accelerates the dechromisafion corrosion rate, decreases the temperature and concentration of HC1 solution, and when the dechromisation occurs it seriously weakens the microstmcture of dechromisation layer. It is concluded that ultrasonic vibration can accelerate destruction of the passivation film on the Cr surface and increase the activities of Cl^- and Cr.     

高温预析出对Al-Zn-Mg-Cu铝合金显微组织、强度和应力腐蚀抗力的影响

通过改变固溶条件 ,对Al Zn Mg Cu高强铝合金采用先高温后低温的两步固溶处理 (高温预析出 )来改善晶内和晶界的析出状态 ,研究了高温预析出对Al Zn Mg Cu铝合金的金相组织、强度和应力腐蚀性能的影响。结果表明 ,4 6 5℃高温预析出在保持较高强度和塑性的同时 ,可以改善合金的抗应力腐蚀性能     

超声振动研磨外圆类陶瓷工件去除率研究

外圆超声振动研磨作为新型有效的外圆类磨削方法，为典型硬脆陶瓷轴类零件的加工提供了高效精密的加工手段。本文介绍了功率超声振动研磨外圆加工装置和加工原理，并结合对Al2O3陶瓷试件的研磨试验，分析了超声研磨中加工参数与试件材料去除率的关系。同时与普通研磨相比较，得出超声研磨加工效率高、加工工件表面粗糙度小的结论。