Study on machining of niobium hafnium alloy material

Niobium hafnium alloy material is a kind of niobium as a base to add a certain amount of hafnium and other elements, has the advantages of high temperature resistance, corrosion resistance, can be used as aircraft, missiles, rockets heat-resistant and high strength materials and control, regulating device parts material. Due to the material itself is not high hardness, tensile property is good, the processing process is easy to appear chip breaking phenomenon, the formation of the accumulation of chip tumors, resulting in the surface roughness of the processed parts, can not meet the design requirements.

In order to solve the problems in the processing of niobium hafnium alloy parts, according to its machining characteristics, surface quality and other factors, through the processing equipment, tool materials, tool geometric parameters, processing parameters and other aspects of the selection of analysis and preliminary processing scheme formulation:

1) the selection of processing equipment: according to the minimum tolerance requirements of the parts to be machined (0.03), the lathe should choose the CNC machining lathe with good turning performance and high equipment accuracy (0.01), in order to achieve the copying processing and tolerance requirements of the parts;

2) tool selection: in the rough machining process, in order to improve the processing efficiency and quality of the product, the tool material selection of high speed steel, carbide diamond and other materials; In order to make the tool always maintain a sharp state, the cutting tool rake Angle, the main Angle of the best control at about 12°, Angle control in 5° ~ 7. In the finishing process in order to increase the heat emission in the cutting process, improve the surface quality of the product, should be selected without the coating of the forming tool for small cutting.

3) Selection of cutting amount:

According to the trial machining experience and theoretical analysis, the machining parameters of rough machining and fine machining are tentatively determined as follows:

A. Rough machining: select machine tool spindle speed control in 300~400r/min or so, back feed is greater than 1mm, feed is 0.1mm/r;

B. Finishing: select spindle speed control in 400 ~ 500 r/min, back feed of 0.2 ~ 0.5mm, feed of 0.05mm/r;

4) Selection of cutting fluid:

In order to avoid tool wear in the process of processing and ensure the sharpness of the tool, diesel oil is selected as the cutting fluid in rough machining and rape oil is selected as the cutting fluid in fine machining.

This article through to NbHf alloy material processing characteristics analysis, formulated the detailed process flow, determined the cutter material, cutter geometric parameters, cutting parameters, the determination of this processing scheme, not only to ensure the surface quality of parts, but also can be used for other niobium hafnium alloy material products processing.