Material Info
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Material Group - Nickel based alloys
The excellent physical properties that characterize Nickel-based high temperature alloys make them ideal for use in the manufacture of aerospace components.
Properties such as high yield strength and ultimate tensile strength, high fatigue strength, corrosion and oxidation resistance even at elevated temperatures, non-magnetic characteristics and low creep, enable the usage of Nickel-based high temperature alloys in many applications and over a very wide temperature spectrum.
The aerospace industry accounts for about 80% of Nickel-based high temperature alloys which are used in rotating parts of gas turbines such as disks and blades, housing components such as turbine casing, engine mounts and in components for rocket motors and pumps.
Nickel-based high temperature alloys, which contain 35-75% Ni and 15-22% Cr, constitute about 30% of the total material requirement in the manufacture of an aircraft engine, and are also used as structural material for various components in the main engine of space shuttles.
With the introduction of Inconel 718 (which is one of the most common Nickel-based high temperature alloys in the aerospace industry) in the year 1960, its usage has seen a tremendous growth in the aircraft industry.
Machining Challenges:
The very same properties that make Nickel-based high temperature alloys such a great high temperature materials also cause high machining difficulties. Metallurgical characteristics like the hard abrasive particles in the materials’ microstructure and the high work hardening rates are primary reasons for the poor machinability.
The cutting forces and temperature at the cutting zone are extremely high due to the high shear stresses developed and the low thermal conductivity. This, coupled with the reactivity of Nickel-based high temperature alloys with the tool material, leads to galling and welding of the chips on the work piece surface and cause excessive tool wear, which can limit cutting speeds and reduce useful tool life. In addition, the high capacity of these materials for work hardening causes depth of cut notches on the tool.
All these characteristics contribute to low material removal rates and short tool life resulting in huge machining costs.
Over the past few years, ISCAR has invested a lot in R&D in order to investigate the machining of Nickel-based high temperature alloys. Our special improved cutting tools along with our unique grades have places ISCAR as a leading company in the area of machining Nickel-based high temperature alloys.
In addition to our standard pressure cooling solutions, the growing demands for high pressure machining solutions especially in the aerospace market, has led ISCAR to develop unique product lines suitable for high pressure cooling systems.
When machining Nickel-based high temperature alloys with standard pressure coolant, the recommended cutting speed is 30-35 m/min. The use of high pressure cooling system enables to increase the cutting speeds by 100-150% and significantly increase the productivity.
