MACHINING OF REFRACTORY MATERIALS. PHASE II. Technical Engineering Report, August 1, 1961-October 31, 1961

Technical Report · Wed Nov 01 04:00:00 EST 1961

OSTI ID:4831841

Nowikowski, L J; Zlatin, N; Field, M

Machining studies were performed on pressed and sintered unalloyed tungsten, TZM molybdenum alloy, unalloyed columbium, D-31 columbium alloy, Rene 4l solution treated to 321 BHN and Rene 41 aged to 365 BHN. The investigation consisted oi turning, face milling, end milling and grinding tests on tungsten; turning, face milling, drilling and grinding tests on molybdenum; drilling and grinding tests on columbium; and drilling, face milling, end milling, slotting and grinding tests on Rene 41. Machinability testing performed to date on 93% dense tungsten has shown the following in turning, a tool life of 19 minutes was obtained with a K-ll carbide at a cutting speed of 100 feet/min, a feed of 0.009 inches/rev and soluble oil. Tool life in face milling was 28 inches of work travel with a 999 carblde at 75 feet/ min, a feed of 0.010 inches/tooth and highly chlorinated oil. End mill slotting with a 1 1/4 in. diameter cutter with K-8 carbide gave a tool life of 45 inches of work travel at 200 feet/min, a feed of 0.003 inches/tooth and soluble oil. Grinding is difficult and G Ratios were low, 1 to 3. TZM molybdenum machines quite well. Cutting speeds of 350 to 400 feet/min can be used in turning and face milling with C-2 grades of carbide. Tool life is 25 minutes in turning with a 0.009 inches/rev feed, and 60 inches of work travel in face milling at a feed of 0.005 inches/tooth. Drilling with M-1 high speed steel drills produced a drill life of 95 holes at a speed of 130 feet/ min, a feed of 0.005 inches/rev, with highly chlorinated oil. The grinding characteristics of TZM, however, are poor and low G Ratios, 4 to 6, were obtained in the surface grinding tests. A drill life of 175 holes was obtained on D-31 columbium with 1/8 in. diameter M-1 high speed steel drills at 75 feet/min, 0.005 inches/rev feed with highly chlorinated oil. G Ratios for unalloyed columbium were low, 2 to 3, for the various grinding conditions investigated. Tables giving specific recommendations for machining Rene 41 in the solution treated and the solution treated and aged conditions are presented in the report. (auth)

• Research Organization: Metcut Research Associates Inc., Cincinnati
• NSA Number: NSA-16-003417
• OSTI ID: 4831841
• Report Number(s): ASD-TR-7-532a(IV)
• Country of Publication: United States
• Language: English

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