环形铣刀铣削拼接淬硬钢模具切削性能研究

发布时间：2018-01-28 04:28

本文关键词： 环形铣刀硬度拼接淬硬钢汽车模具切削性能刀具磨损　出处：《哈尔滨理工大学》2017年硕士论文　论文类型：学位论文

【摘要】：近年来,随着汽车、航天、造船等工业的发展,模具需求量越来越大。模具钢Cr12MoV具有淬火后变形小、耐磨性强、适应冲压力大、加工寿命长等优点而广泛应用于汽车覆盖件模具制造中。为了保证汽车覆盖件保持高品质的大量生产、提高淬硬钢模具的刚度、提高耐用度和加工精确度等,需要对淬硬钢覆盖件的某个局部进行淬火,用于提高冲击较大部位的耐用度。淬硬钢在局部淬火后,拼接成整体后模具之间产生硬度差,致使后续的半精加工以及精加工时铣削加工特性复杂,刀具容易发生变形、容易加速刀具的磨损和破损,致使被加工工件尺寸精度和表面质量等指标难以保证,也会使后续人工磨削量增大,因此对刀具在加工拼接部分工件的性能研究尤为重要。针对上述问题本文开展了环形铣刀铣削拼接工件情况下的切削力建模、刀具磨损、刀具寿命以及表面质量的研究,主要内容包括:首先,设计了环形铣刀铣削拼接淬硬钢切削试验,试验参数中包含了对切削力、刀具磨损和加工质量具有重要影响的切削用量、过缝方式和过缝角度等因素。为后续分析提供了数据支持。其次,运用微元几何法建立了环形铣刀切削力模型,该模型可用于预测不同硬度材料的铣削力,之后利用Matlab对铣削力进行了数值仿真,最后还通过实验验证了模型的准确性。然后,进行了环形铣刀铣削加工拼接淬硬钢的磨损特性的研究。首先在切削刃上逐渐形成磨损楞带,同时伴随出现微崩刃。然后随着切削的进行,磨损区域由切削刃逐渐扩展至前后刀面,前刀面逐渐形成月牙洼,后刀面涂层逐渐脱落,磨损区域不断扩大,刀具基体材料的磨损,最后直至刀具破碎失效。主要磨损机理为磨粒磨损,而随着磨损的加剧后刀面磨损区域逐渐增大,并逐步转化为扩散磨损以及氧化磨损等磨损机理。最后,开展了环形铣刀铣削加工拼接淬硬钢加工表面质量研究,获得了铣削加工过程过缝方式和过缝角度对切缝区表面质量影响规律,以及刀具磨损对切削力和表面粗糙度影响规律,为环形铣刀在切削拼接淬硬钢应用提供技术支持。
[Abstract]:In recent years, with the development of automobile, spaceflight, shipbuilding and other industries, the demand for dies is increasing. The die steel Cr12MoV has the advantages of small deformation after quenching, strong wear resistance and large impact pressure. In order to ensure the high quality mass production of automobile panels, improve the rigidity of hardened steel dies, improve the durability and processing accuracy, etc. It is necessary to quench some part of the hardened steel cover to improve the durability of the larger impact parts. After the hardening steel is partially quenched, the hardness difference between the dies is produced after splicing into a whole. As a result of the subsequent semi-finished machining and finishing milling processing characteristics are complex, the tool is prone to deformation, easy to accelerate tool wear and damage, resulting in the machining of workpiece dimension accuracy and surface quality index is difficult to ensure. It will also increase the amount of subsequent manual grinding, so it is particularly important to study the performance of cutting tools in the machining of spliced parts. In view of the above problems, the cutting force modeling of annular milling cutter milling stitched workpieces is carried out in this paper. Research on tool wear, tool life and surface quality. The main contents are as follows: firstly, the cutting test of ring milling cutter is designed, and the cutting force is included in the test parameters. Tool wear and machining quality have an important impact on cutting parameters, overslit mode and overslit angle, which provide data support for subsequent analysis. Secondly, the cutting force model of annular milling cutter is established by means of micro-element geometry method. The model can be used to predict the milling force of different hardness materials, and then the milling force is simulated by Matlab. Finally, the accuracy of the model is verified by experiments. The wear characteristics of bonded hardened steel in annular milling cutter milling were studied. Firstly, the worn corrugated strip was gradually formed on the cutting edge, followed by the appearance of micro-disintegrating edge. Then with the cutting process. The wear area is gradually extended from the cutting edge to the front of the tool surface, the front tool surface gradually forms a crescent hole, the coating on the rear tool surface gradually falls off, the wear area expands continuously, and the tool matrix material is worn. Finally, the main wear mechanism is abrasive wear, and with the increase of wear, the wear area of the tool surface gradually increases, and gradually transformed into diffusion wear and oxidation wear mechanism. Finally. The surface quality of hardened steel in annular milling was studied, and the influence of overslit mode and overseam angle on the surface quality of cutting zone was obtained. The influence of tool wear on cutting force and surface roughness provides technical support for the application of annular milling cutter in cutting joint hardened steel.
【学位授予单位】：哈尔滨理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TG54

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