Research On Super Alloy GH4169 Cutting Technology

In the field of aero-engines,the super alloy, which is known as "the cornerstone of advanced engine" has attracted more and more attention. With good mechanical properties,the super alloy become indispensable material of missiles, aircraft engines, gas turbines and other hot end parts, while its characteristic such as high strength, high hardness, low thermal conductivity and high elongation lead to low processing efficiency and poor quality. In the actual processing, the cost of production will increase sharply if the selection of cutting parameters or tool is unreasonable. Therefore, it is imperative to do the study of the super alloy cutting theory in aero-engine manufacturing industry.This study comprehensively researches on the process of turning and milling for nickel-based super alloy GH4169. Through logically – designed orthogonal experiment combined with regression algorithm, the effect of processing parameters on cutting force,cutting temperature and tool life is analyzed and the corresponding empirical formula is summarized. The results are verified in the actual production process. By using scanning electron microscopy and energy dispersive spectroscopy to analyze the position of tool wear,a law of tool wear is concluded, which provides a theoretical support for reasonably selecting machining parameters, drawing up machining plans and improving processing quality.The results shows that, when coating cutting tool, whose substrate material is cemented carbide, processes GH4169, the cutting force is changed obviously with the depth of cut increasing. And the effect caused by the change of cutting temperature and cutting tool life is more outstanding when cutting speed and feed rate are changed. At low speed, tool wear is mainly crater wear on the rake face and exfoliation from flank surface. When cutting speed increases, the flank surface wear of tools becomes faster and also tipping occurs at the tip. To continue processing will result in tool failure, and ultimately tool will lose processing capacity.Cementation, friction and oxidative wear are the main wear mechanism.Finally, processing costs and efficiency as optimization objective, combined with empirical formula, are verified by machining parts on site. The optimal processing parameters are proved as more reasonable, which have achieved the goal of optimum processing efficiency and profit, with a strong guiding significance for the actual production.