强流脉冲电子束强化齿轮弯曲疲劳性能研究

发布时间：2018-05-29 01:21

本文选题：齿轮 + 强流脉冲电子束　；参考：《重庆理工大学》2011年硕士论文

【摘要】：齿轮工作时受力情况复杂,时常会产生多种失效,如点蚀、剥落、磨损、胶合、疲劳折断等,而疲劳折断在齿轮的所有失效中占据较大比例。现代工业的发展要求齿轮既要轻质又要高强度。国际上对齿轮弯曲疲劳强度的研究主要在齿形的改进、齿轮表面处理方面,但在一定条件下,齿形的改进对提高齿轮弯曲疲劳强度的作用是有限的,传统的表面处理技术也面临一些局限,因此,寻找表面处理新技术在齿轮上的应用具有重要意义。强流脉冲电子束(HCPEB)技术是一种新型高效的表面处理技术,它具有高能量密度、高效率等特点,可以直接、有效地改变或改善材料的表层组织、结构和性能。本课题来源于国家自然科学基金资助项目“齿轮表面非晶化工艺与性能研究”(编号: 50775229),利用强流脉冲电子束对表面未经磨削和经过磨削的原始齿轮进行表面照射处理,在高频疲劳实验机上对原始齿轮与照射齿轮进行弯曲疲劳测试,研究强流脉冲电子束对不同表面状况齿轮的弯曲疲劳性能的影响,以获得具有更长疲劳寿命的齿轮。论文主要工作有: (1)总结了影响齿轮弯曲疲劳强度的主要因素。 (2)采用ANSYS有限元软件中的热力耦合方法,对脉冲电子束照射40Cr钢过程的温度场和热应力场进行了有限元模拟分析,并给出了多次照射后的表面残余应力。 (3)直接用工艺参数经过优化的强流脉冲电子束对未经磨削与经过磨削的两种表面状态的齿轮进行表面处理。 (4)在恒幅载荷条件下,对所有齿轮进行弯曲疲劳强度测试,并对未磨削齿轮和磨削齿轮电子束照射前后的弯曲疲劳强度进行了比较。 (5)通过显微硬度、表面粗糙度、表面残余应力测试,齿根表面形貌及截面轮廓、表层显微组织观察,对齿轮弯曲疲劳性能变化原因进行了深入分析。结果表明:未磨削的齿轮经电子束照射后,其弯曲疲劳强度得到一定程度的降低;而经磨削过的齿轮经电子束照射后,其弯曲疲劳强度稍有提高。论文的结论对齿轮电子束表面改性将起到一定的指导作用。
[Abstract]:When the gear is working, it often produces many kinds of failure, such as pitting, peeling, wear, gluing, fatigue breaking and so on. Fatigue fracture accounts for a large proportion of all the gear failures. The development of modern industry requires gears to be both light and high strength. The research on the bending fatigue strength of gears in the world is mainly focused on the improvement of gear profile and surface treatment of gears, but under certain conditions, the improvement of tooth shape is limited in improving the bending fatigue strength of gears. Traditional surface treatment technology is also faced with some limitations, so it is of great significance to find new surface treatment technology in gear. High current pulsed electron beam (HCPEB) technology is a new and efficient surface treatment technology, which has the characteristics of high energy density and high efficiency. It can directly and effectively change or improve the surface structure, structure and properties of materials. This subject comes from the project "Research on the amorphous process and performance of Gear Surface", funded by the National Natural Science Foundation of China (No. 50775229). The surface of unground and ground original gears is irradiated by intense pulsed electron beam. In order to obtain the gear with longer fatigue life, the bending fatigue of the original gear and the irradiated gear was measured on the high frequency fatigue test machine, and the influence of high current pulse electron beam on the bending fatigue performance of the gear with different surface conditions was studied in order to obtain the gear with longer fatigue life. The main work of the thesis is as follows: The main factors affecting the bending fatigue strength of gears are summarized. The temperature field and thermal stress field of 40Cr steel irradiated by pulsed electron beam are simulated and analyzed by using the thermo-mechanical coupling method of ANSYS finite element software. The surface residual stress after multiple irradiation is given. (3) Surface treatment of gears with unground and ground surface states is carried out directly by using highly current pulsed electron beam with optimized process parameters. The bending fatigue strength of all gears was tested under constant amplitude loading and the bending fatigue strength of unground gears and grinding gears before and after electron beam irradiation was compared. Through microhardness, surface roughness, surface residual stress test, tooth root surface morphology and cross-section profile, surface microstructure observation, the causes of gear bending fatigue properties were analyzed. The results show that the bending fatigue strength of unground gears decreases to a certain extent after electron beam irradiation, but the bending fatigue strength of grinding gears is slightly increased after electron beam irradiation. The conclusion of this paper will play a guiding role in the surface modification of gear electron beam.
【学位授予单位】：重庆理工大学
【学位级别】：硕士
【学位授予年份】：2011
【分类号】：TH132.41

【相似文献】