钴基高温合金的高速铣削及其参数优化研究-机械制造及其自动化专业论文.docxVIP

南京航空航天大学硕士学位论文 摘 要 高温合金是航空航天领域应用广泛的难加工材料之一。由于其导热系数小、摩擦系数大、 加工硬化严重等原因，导致加工高温合金时，出现切削力大、切削温度高、刀具磨损严重等现 象，从而影响了高温合金的加工效率和质量。本文以钴基高温合金(GH5188)为研究对象，对其 高速铣削加工性进行了比较深入的研究，并在试验结果的基础上对其高速铣削加工工艺参数进 行了优化。 本论文主要研究工作如下： (1) 使用硬质合金刀具对钴基高温合金(GH5188)进行了高速铣削试验。研究了切削参数对 切削力、刀具耐用度及加工表面粗糙度的影响；建立了切削力、表面粗糙度及刀具耐用度的经 验公式；并与常用镍基高温合金(GH4169)的铣削加工性进行了比较，为实际加工 GH5188 提供 参考；研究了刀具后刀面磨损对铣削力、加工表面粗糙度的影响。 (2) 对钴基高温合金高速铣削参数进行了优化研究。以最大生产效率、最低加工成本为优 化目标，以工件、机床、刀具及加工要求为约束条件，建立了多目标参数优化模型。利用 Matlab 遗传算法工具箱和图形用户界面工具箱(GUIDE)开发了参数优化软件，并在给定条件下获得 了参数优化结果。 关键词：钴基高温合金，高速铣削，铣削力，刀具磨损，参数优化，遗传算法 I 钴基高温合金的高速铣削及其参数优化研究 Abstract Superalloy is one of the hard-to-cut materials which are widely used in aerospace industry. For its small coefficient of thermal conductivity, big coefficient of friction and seriousness of work-hardening, phenomena of big cutting force, high cutting temperature and seriousness of tool wear appear, thus, the efficiency and quality of superalloy machining are influenced. In this paper, the high speed milling machinability of GH5188 Co-based superalloy, which is the object of study, is intensively researched, and based on the experiment result, the process parameters of high speed mil- ling this material are optimized. The main research work completed follows: High speed milling of GH5188 Co-based superalloy experiments are carried out using hard alloy tools. The influence of cutting parameters to cutting force, tool life and surface roughness of work- piece is researched; the empirical formulas of cutting force, surface roughness and tool life are estab- lished. Compared with the milling machinability of conventional nickel based superalloy GH4169, the results can provide reference to actual machining. The influence of the tool flank wearing to milling force and surface roughness of workpiece is also researched. The high speed milling parameters of cobalt based superalloy is optimized. Optimal model of multiple-target parameters, which takes the maximum production efficiency and minimum machini