激光熔凝耦合仿生形态对滚动导轨耐磨性能影响的研究

发布时间：2019-07-10 12:07

【摘要】：中国作为制造大国提出了“中国制造2025”的强国战略,研发高精度、高效率的机床是提升制造业整体水平的基础保障。相比于滑动轨导,滚动导轨的定位精度更高、摩擦系数更小、精度保持性更好。滚动导轨表面在往复循环的疲劳应力作用下会出现裂纹和疲劳剥落,这对导轨精度保持性和耐磨性能构成了威胁,导轨一旦失效将很难修复。利用仿生与激光表面处理相结合的耦合仿生强化技术是提高材料表面耐磨性的一个新研究方向。(1)本文模仿自然界生物的特征设计了几种等激光强化面积的不同仿生特征,利用激光熔凝技术将其加工在导轨块试样表面并对其进行了摩擦磨损实验,目的是为了探究仿生形态是如何影响导轨性能以及不同仿生形式之间存在差异的机制。(2)用弹性迟滞理论分析了耦合仿生技术对提高材料耐磨性能的影响。经过激光熔凝处理的HT250其材料表面压缩区的恢复阻力约为未处理材料的三分之一,这说明了激光熔凝技术能有效地减少滚动过程中由弹性迟滞引起的材料力学损耗,提高材料表面的耐磨性能。(3)设计摩擦磨损实验台并对耦合仿生导轨块试样进行了磨损实验。模仿实际机床导轨并设计、搭建了实验效率高、控制实验变量条件能力强的往复式摩擦实验台,并分4次进行了疲劳磨损实验,累计磨损次数达1.68×106次。(4)通过XDR实验、SEM扫描电镜实验、显微硬度测试以及3D形貌测试对摩擦磨损实验结果进行了分析。观察发现经过激光熔凝处理的试样块其组织中硬度较低、间隙较大的珠光体变成了硬度大、组织细密的针状马氏体和少量奥氏体;且各耦合仿生导轨式样块表面的硬度及表面轮廓高度算术平均值Sa存在一定的差异。(5)实验结果表明仿生形态对材料表面的耐磨性能有着重要的影响;等激光强化面积的各耦合仿生导轨试样块在抗磨、耐磨能力上存在一定的差异;仿潮间带贝壳类纵剖面珍珠层的砖墙形单元体、蜜蜂蜂巢的蜂巢形单元体具有突出的抗磨损能力。
文内图片：

图片说明：仿生单元体的提取Fig.2.1Extractionofbionicunit2.1.2仿生单元的设计
[Abstract]:As a manufacturing country, China has put forward the strategy of "made in China 2025". The research and development of high precision and efficient machine tools is the basic guarantee to improve the overall level of manufacturing industry. Compared with the sliding rail guide, the rolling rail has higher positioning accuracy, smaller friction coefficient and better precision retention. Cracks and fatigue spalling will occur on the surface of rolling guideway under the action of fatigue stress of reciprocating cycle, which threatens the precision retention and wear resistance of rolling guideway, and it will be difficult to repair once the guideway fails. The coupling bionic strengthening technology combined with bionic and laser surface treatment is a new research direction to improve the surface wear resistance of materials. (1) in this paper, several bionic characteristics of equal laser strengthening area are designed according to the characteristics of natural organisms, and the laser melting technology is used to process them on the surface of guideway block samples and friction and wear experiments are carried out. The purpose of this paper is to explore how bionic morphology affects the performance of guideway and the mechanism of differences among different bionic forms. (2) the influence of coupling bionic technology on improving wear resistance of materials is analyzed by elastic lag theory. The recovery resistance of the surface compression zone of HT250 treated by laser melting is about 1/3 of that of the untreated material, which shows that the laser melting technology can effectively reduce the mechanical loss of the material caused by elastic lag in the rolling process and improve the wear resistance of the material surface. (3) the friction and wear test bench is designed and the wear test of the coupled bionic guideway block sample is carried out. A reciprocating friction test platform with high experimental efficiency and strong ability to control experimental variables was built, and the cumulative wear times were 1.68 脳 106 times. (4) the friction and wear test results were analyzed by XDR experiment, SEM scanning electron microscope test, microhardness test and 3D morphology test. It is found that the hardness of the sample blocks treated by laser melting is low, the pearlite with large gap becomes a large hardness, the fine structure of acicular martensite and a small amount of Austenite, and there are some differences in the surface hardness and surface profile height Sa of each coupled bionic guide rail sample block. (5) the experimental results show that the bionic morphology has an important effect on the wear resistance of the material surface, and the surface hardness and surface profile height of the coupling bionic guide rail sample block are different. (5) the experimental results show that the bionic morphology has an important influence on the wear resistance of the material surface. There are some differences in wear resistance and wear resistance of each coupling bionic guideway sample block with equal laser strengthening area, and the brick wall unit body with shell longitudinal profile pearl layer and the honeybee nest cell body have outstanding wear resistance.
【学位授予单位】：太原科技大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TG502;TG665

【参考文献】