Second in a series on nitrogen-based controlled atmosphere'techniques issued by Airco Industrial Oases.
New concepts in controlled atmospheres: Nitrogen-Based Sintering.
microstructure and mechanical properties. The part shown here, produced from a powder blend of iron, 2.5% copper, 0.85% graphite and 1% lubricant, and pressed to give a 6.5 g/cc density, was sintered at 2050°F with 30 minutes in the hot zone both in a conventional endo-gas atmosphere and in Airco's nitrogenbased atmosphere. The results:
Natural gas, commonly used to produce sintering atmospheres such as endo-gas, dissociated ammonia and exo-gas, is in critically limited supply and becoming increasingly expensive. What's needed, clearly, is a dependable Tooth Crush C o 1 substitute sintering atmosphere which is 1 Atmosphere Dimensions RB Strength (in-lbs) (PPM) 1 (%) plentiful, economical, technically suitable 0.80 4600 1 1 Endo 62 165 Acceptable and independent of natural gas. Airco's 3-year research program to 1 Airco 0.83 4100 1 Acceptable 79 178 develop a nitrogen-based sintering process, In addition to being independent of natural fortunately, is now complete. And it couldn't come gas, the nitrogen-based process saves energy, at abetter time. requires no capital investment, can be used in existing furnaces without modifications, and is inherently safe, consistent, reliable and flexible. You are invited to use our facilities to sinter your own green parts under actual production conditions and evaluate the results. Airco has also developed innovative nitrogen-based atmosphere techniques for carburizing, nitriâing, bright annealing, carbonitriding, neutral hardening, annealing and brazing. We have all the back-up and facilities youTI need. Complete laboratory. Productionscale belt, pit, bell and integral-quench furnaces. Comprehensive analytical services and The new equipment. Unique atmosphere blending and flow atmosphere, first control systems. Hue a knowledgeable and reported at the 1976 International Powder Metal experienced technical service staff. Conference in Chicago, was developed on Airco's For mora details on any of the new Airco 18-inch belt sintering furnace at our Central controlled atmosphere techniques, call or write Research Labs in Murray HQl, New Jersey. Bob Beck, Manager-Controlled Atmospheres It is produced by mixing inert, pure, dry Group, Airco Industrial Gases, 575 Mountain nitrogen with small, carefully controlled amounts Ave., Murray Hill, NJ 07974. À ι π ρ η of "active" ingredients to control oxide reduction, (201)464r8100. carbon potential, strict dimensional accuracy, idustna bases L U I I T S J I L J PJ_II
CIRCLE 25 ON READER SERVICE CARD Aug. 14, 1978 C&EN
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