Analysis and experimental study of the cutting mechanism in machined nickel-base superalloys GH4169 with PCBN tools under high pressure cooling

ABSTRACT

In view of the problem of superalloy difficult to be processed, high pressure cooling is used for machining. In this paper the chip breaking model is described and the cutting force characteristics is analyzed firstly under high pressure cooling, which is combined with theoretical knowledge of cutting mechanism under conventional pressure cooling. After that, the experimental research on machining nickel-base superalloy with PCBN tools is carried out. The result shows that the bending moment of the chip is increased and the chip curling radii is decreased by the high pressure cooling, which eventually leads to the increase of the chip strain and the fracture of the chip. By the high pressure cooling, the ability of the coolant to penetrate the contact area of the tool-chip is improved, which improves the lubrication effect in the contact area of the tool-chip, and eventually leads to the reduction of cutting force. The above research results lay a theoretical foundation for machining superalloy under high pressure cooling.

KEYWORDS:

• Superalloy
• high pressure cooling
• cutting mechanism
• PCBN tools

Funding

This project is supported by National Natural Science Foundation of China(Grant No. 51475128), the Natural Science Foundation of Heilongjiang Province of China (E2016043) and the Center of Engineering Technology of Harbin (2014ADAG003).