Accession Number:

AD0872307

Title:

Development of Improved Cutting Tool Materials.

Descriptive Note:

Final technical rept. 16 Dec 66-15 Dec 69,

Corporate Author:

IIT RESEARCH INST CHICAGO IL

Personal Author(s):

• Holtz, Frederick C.
• Morrow, Hugh, III

Report Date:

1970-05-01

Pagination or Media Count:

312.0

Abstract:

New cutting tool alloys were developed for machining aerospace materials. Co-Cr and Fe-Co base alloys were prepared by hot-consolidation of atomized powders. Fe-50Co-20W-1.3C at RC 66 attained a transverse-rupture strength f 790,000 psi, an ultimate tensile strength of 443,000 psi, and had tool lives 2 to 3 times those of M40-type high-speed steels in peripheral end milling Ti-6Al-4V. Alloys of Fe-Co-W-C at 30-40 Co hardened to RC 72.5 and were superior to high-speed steels in turning Ti- and Ni-base alloys. Extrusion and edge-restraint rolling were used to fabricate 3 to 12 lb billets of atomized Fe-Co-W-C alloy powders. The bar stock was highly fabricable and defect-free. Composite bar stock was produced by extrusion or rolling jacketed Fe-Co base tool alloy powders on mild steel cores. High-melting matrix carbides based on TiC-Ni-Re were prepared by liquid-phase sintering. Small additions of Ta or W produced bend strengths up to 175,000 psi at RA 93 hardnesses of RA 86 were retained to 1500F. These carbides had 2 to 3 times the tool life of commercial C-8 grade carbides in turning AISI 4340 at RC 42. Arc-melted Hf-Ta alloys were hot rolled, machined, then nitrided to produce hard surface layers. Author

Descriptors:

• (*CUTTING TOOLS
• MATERIALS)
• COBALT ALLOYS
• CHROMIUM ALLOYS
• IRON ALLOYS
• CARBIDES
• HAFNIUM ALLOYS
• TANTALUM ALLOYS
• POWDER METALLURGY
• RHENIUM ALLOYS
• NICKEL ALLOYS
• MANUFACTURING

Subject Categories:

• Metallurgy and Metallography
• Machinery and Tools

Distribution Statement:

APPROVED FOR PUBLIC RELEASE