Metallic cryogenic tempering method for improving milling stability

Abstract

The invention discloses a metallic cryogenic tempering method for improving milling stability. The method includes: (a), assembling a liquid nitrogen cooling nozzle, synchronously moving with a milling machine spindle and an end mill, to the milling machine spindle and the arranged end mill; (b), executing climb milling under the condition of cryogenic cooling, and performing experiment calculation to obtain cutting force coefficients of tangential milling force coefficients, tangential cutting edge force coefficients, radial milling force coefficients, radial cutting edge force coefficients and the like; (c), executing hammer test on a point of a milling cutter, acquiring a corresponding displacement frequency response function based on test result fitting, and extracting modal parameters such as modal mass, modal damping and modal stiffness; (d), constructing a two-degree-of-freedom milling dynamics equation, then predicating stability boundaries in the metal milling process based on the dynamics equation, and correspondingly adjusting the milling parameters. By the method, the problems of cutting heat and cutting process system unstability can be solved comprehensively, and the maximum chatter-free material removal rate of cryogenic tempering is significantly increased.

Description

technical field [0001] The invention belongs to the technical field of milling processing technology, and more specifically relates to a metal cryogenic processing method for improving milling stability. Background technique [0002] In various metal milling processes, coolant has been widely used. Spraying coolant to the cutting area can effectively reduce the friction coefficient between the tool and the workpiece material, and take away most of the incoming tool, workpiece and chips. The cutting heat can reduce the cutting temperature and improve the surface processing quality. However, for difficult-to-cut materials such as titanium alloys and superalloys that are widely used in the aerospace industry, a large amount of coolant is required and conservative process parameters are selected to ensure sufficient tool life and reliable surface quality, so the material removal rate and because the cooling liquid itself is harmful to the operators and the environment, its recy...

AI Technical Summary

Problems solved by technology

Tests have shown that if the critical depth of cut is exceeded during the milling process, the process system will be unstable and chatter, resulting in excessive vibration displacement between the tool and the workpiece, and even cause tool damage and workpiece scrapping. Therefore, the stability of the cutting process is the first choice. The primary problem when processing parameters

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