DEVELOPMENT OF IMPROVED CUTTING TOOL MATERIALS.
Final rept. 25 Jan-15 Dec 66,
IIT RESEARCH INST CHICAGO IL
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New tool materials were developed to achieve increased cutting efficiency. High-speed steels of the M2 type were enriched in titanium, hot worked, then solid-state carburized. These tools showed a permissible cutting speed increase of about 35 compared to commercial RC 70 type high-speed steel when used for turning AISI 4340, RC 44. Similar increases in cutting performance were measured for cast-to-shape tools based on M1 high-speed steel containing 10 V, up to 2 Ti and 3.5 C. Age-hardenable cobalt-base tool alloys were prepared by the hot working of atomized powders. The most promising alloy was Co-45Cr-15W-2.5C, which exhibited a permissible cutting speed increase of 120 over the commercial cast cobalt-base tool alloy in turning the RC 44 steel a speed increase of 35 was achieved in turning AISI 4340 at RC 52. Cemented carbide tool alloys having matrix melting points near 1800 C 3270 deg F were prepared by liquid-phase sintering or arc-melting Compositions in the Cb-V-C and Ti-V-C systems were the most promising. Initial studies of arc-melted 80Hf-20Ta, nitrided at 1930 C 3500 F, showed a cutting speed capability similar to that of commercial alumina tools on AISI 4340, RC 44.5. Author
- Machinery and Tools