High-precision titanium-alloy thin-walled ring gear machining method

Abstract

The invention relates to the field of machining, in particular to a high-precision titanium-alloy thin-walled ring gear machining method. The method includes the following steps: blank forging, rough turning of a blank, annealing, rough turning of a gear blank, heat treatment, half-finish turning, heat treatment, finish machining and heat treatment. For finish machining, a special clamp is used on a machine tool to clamp a workpiece, the gear blank is subjected to finish machining, and ring process bosses are removed layer by layer; for the last heat treatment, thermocycling is performed twice to further stabilize the structure, stabilize workpiece dimension and eliminate tooth surface stress. The machining process is simple, deformation of parts in machining is eliminated in the machining process, machining quality and dimensional accuracy of the workpiece can be guaranteed, and the dimension and quality of the workpiece are further stabilized by repeated heat treatment.

Description

technical field [0001] The invention relates to the field of mechanical processing, in particular to a method for processing titanium alloy high-precision thin-walled ring gears. Background technique [0002] The deformation problem of titanium alloy high-precision thin-walled ring gear has become a difficult point in processing. A gear with grade 6 precision. The material is titanium alloy TC4. The concentricity of the addendum circle relative to the reference inner ring hole and the verticality of both ends relative to the reference inner ring hole are high. Moreover, the gear is a typical thin-walled part with poor rigidity and easy deformation. Titanium alloy material has low thermal conductivity and small elastic modulus, so its material rigidity is also poor, and it is not easy to process and make thin-walled parts. Titanium alloy materials have good mechanical, chemical, physical and other comprehensive properties: ① light weight, but its specific strength / density i...

AI Technical Summary

Problems solved by technology

A gear with grade 6 precision. The material is titanium alloy TC4. The concentricity of the addendum circle relative to the reference inner ring hole and the verticality of both ends relative to the reference inner ring hole are high. Moreover, the gear is a typical thin-walled part with poor rigidity and easy deformation. Due to the small thermal conductivity and elastic modulus of titanium alloy materials, the rigidity of the material itself is also poor, and it is not easy to process thin-walled parts

Titanium alloy materials have good mechanical, chemical, physical and other comprehensive properties: ① light weight, but its specific strength / density is 23-27, which is the highest among metal materials; ② titanium alloy materials have high thermal stability, and the working temperature can reach 500 ℃, its strength is 10 times higher than that of aluminum alloy at 300-350 ℃; ⑧ good corrosion resistance, dense and firm oxide film can be formed on the surface, and its corrosion resistance is better than stainless steel; ④ thermal conductivity is small, elastic Small modulus, poor rigidity, large deformation, not suitable for making slender shafts and thin-walled parts

Titanium alloy has poor cutting performance and is a typical difficult-to-cut material. The difficulties are reflected in: ① low thermal conductivity, poor heat dissipation and cooling effect during cutting, and easy to form high temperature in the cutting processing area; ② titanium alloy material has small elastic modulus , High yield strength, large amount of rebound after processing deformation. Causes severe friction, adhesion, and bond wear on the flank of the tool; ③The small deformation coefficient is a remarkable feature of titanium alloy processing, even less than 1. The contact length between chips and the front of the tool is very short, and the cutting force per unit area is large, concentrated at the tip of the cutting tool, which can easily cause chipping; ④Titanium alloy has high chemical activity, and it is easy to react with the tool material at high temperature to form a molten metal. Application, diffusion, sticking knife, burning knife and other phenomena