铸造高温合金承力机匣内孔高效加工技术研究

发布时间：2019-04-27 15:18

【摘要】：高温合金具有优良的耐高温特性,是航空发动机热端部件的主要材料,亦是典型的难加工材料。高温合金按制备工艺可分为变形高温合金、铸造高温合金和粉末冶金高温合金,其中,铸造高温合金在铸造时不可避免地面临缩孔缩松等缺陷,为保证铸件的质量,需合理使用冒口、冷铁、补贴以实现顺序凝固,补贴需要后续加工去除,且去除余量大,为加工带来一定困难。本文针对铸造高温合金典型件承力机匣开展车削、磨削加工技术研究,以期实现对机匣内孔断续及连续结构的高效、低成本加工。主要内容如下:(1)针对断续和连续切削,研究涂层硬质合金刀具内圆车削时切削速度和进给量对切削力、切削温度的影响,为后续分析刀具磨损提供依据。(2)研究了两种结构下,切削参数对刀具寿命的影响规律,跟踪观察刀具的磨损形态,结合切削力和切削温度,借助扫描电镜分析刀具的磨损形式和磨损机理。综合分析切削参数对材料去除率和刀具耐用度期间材料去除量的影响,为实际生产中工艺参数的优化提供参考。(3)在车床上搭建试验平台,实现磨削功能,针对断续结构,尝试以端面磨削和内圆磨削的方式去除材料,以磨削比、材料去除率和砂轮耐用度期间的材料去除量为指标,研究工艺参数和砂轮特性对磨削性能的影响。
[Abstract]:Because of its excellent high temperature resistance, superalloy is the main material of hot-end parts of aero-engine, and it is also a typical difficult-to-process material. Superalloys can be divided into deformation superalloy, casting superalloy and powder metallurgy superalloy according to the preparation technology. In order to ensure the quality of castings, casting superalloys inevitably face defects such as shrinkage and shrinkage during casting. Reasonable use of riser, cold iron, subsidies to achieve sequential solidification, subsidies need to be removed by subsequent processing, and the removal of a large amount of surplus, for the processing of a certain difficulty. In this paper, turning and grinding technology of bearing casing for typical cast superalloy parts are studied in order to realize high efficiency and low cost machining of discontinuous and continuous structure of casing inner hole. The main contents are as follows: (1) for intermittent and continuous cutting, the effects of cutting speed and feed on cutting force and cutting temperature of coated cemented carbide cutting tools are studied. (2) the influence of cutting parameters on tool life under two kinds of structures is studied, and the wear morphology of tool is tracked and observed, combined with cutting force and cutting temperature, the cutting force and cutting temperature are combined with cutting force, cutting temperature, cutting force and cutting temperature. The wear form and wear mechanism of the tool were analyzed by scanning electron microscope (SEM). The influence of cutting parameters on material removal rate and material removal amount during the period of tool life is comprehensively analyzed in order to provide reference for the optimization of process parameters in practical production. (3) an experimental platform is built on a lathe to realize grinding function, aiming at intermittent structure. The effects of process parameters and grinding wheel characteristics on grinding performance were studied by means of end grinding and inner circle grinding. The grinding ratio, material removal rate and material removal amount during the duration of grinding wheel were taken as the indexes to study the effects of process parameters and grinding wheel characteristics on grinding performance.
【学位授予单位】：南京航空航天大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TG51;TG580.6

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