Lean High Performance Alloys Containing Manganese as the Primary Alloying Element

1. Lean High Performance Alloys Containing Manganese as the Primary Alloying Element Dennis Hammond Apex Advanced Technologies LLC

2. Manganese Background • Manganese metal admixed subject to hydrolysis, oxidation in P/M application • Manganese as a pre-alloy, hard to compress, limited use levels • Ferro Manganese abrasive, patents • Highest performance alloying element- strength, hardenability • Previous work demonstrated feasibility of using Manganese metal admixed

3. Manganese Background Cont. • Manganese as an admix demonstrated feasibility in multiple production furnaces in previous work • Manganese coated for protection from hydrolysis and oxidation during blending, storage and handling, supplied as master batch • Press conditions developed for maximizing protection during de-lubing and sintering

4. Key FeaturesAdditive/Lubricant Master Batch • Calculations for feasibility of density, desired lubrication, and needed additives • Target volume 98.5-99.5% of theoretical at target green density • Need for a green compact free of density gradients, semi-hydrostatic • Need for excellent lubrication, Apex Superlube® • Need for mobile lubricant to achieve best fit of metal particles during compaction and spread of additives

5. Key FeaturesAdditive/Lubricant Master Batch • Need for excellent distribution and dispersion of additives in a segregation free powder mix and compact • Protection of reactive additives by coating particles • Master batch includes all additives including proprietary additives, pre-mixed and screened, ready to mix with iron powder for easy mixing

6. Customer Goals • Lower alloy cost and content • Ability to be formable, e.g. roll forming the teeth of a gear • Tough properties • Able to be carburized, case hardened • Higher density • Good response to sinter hardening/with better than conventional properties • Ability to get higher sintered densities than conventional sinter hardenable products

7. Scope of Previous Work

8. Optimized Mn Lean Alloys

9. Process Conditions & Equipment • Slugs 3.5 inch Dia. x .9 inch, 2 lbs, 550 ton Cincinnati press, Impact bars, 350Ton Sinterite Best press • Sinterite belt furnace with turbo cooler 2050 slow cool (sc) 30min, 60 min, 2050 fast cool (fc) 30min, 60Min • CM batch furnace, 2250F, 2350F (sc), annealed • Abbott pusher with Varicool 2350 (fc) • Heat treat 40 min., 1550F, 0.85% C, temper 350-400F

30. Production Example • 0.75% Mn, 0.85%C, slow cooling belt furnace, 90N/10H,7.15-7.2g/cc G.D. • Copper infiltrated to7.6g/cc for threading and plating • Requirements of wrought part 250 ft-lbs torque • Mn alloy tested at 650 ft-lbs with easy tapping and good finish

31. Example Part

32. Conclusions • Manganese primary contribution to properties • Higher than normal hardness for P/M both with case hardening and sinter hardening • Carbon loss normal at 2050F ( 0.05% C ) with Manganese and Carbon, higher loss with higher temperature, higher loss with higher Cr content (.12 to .2% C)