Gear fundamentals — a guide to PM gears

Gear fundamentals — a guide to PM gears

speed active micron flaked impact proceedure, with surface agents was used to apply a subthick coating. A little of the coating off. increased by SI...

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speed active micron flaked

impact proceedure, with surface agents was used to apply a subthick coating. A little of the coating off.

increased by SIC, With both values of 565 MPa and 105 GPa were found for tensile strength and elastic modulus.

Metal MICROSTRUCTURAL CHARACTERIZATION CONSOLIDATED ALUMINIDE

OF HIP TRI-NICKEL

H.Q. Ye et al. (Chinese Academy of Sciences, Shenyang, China.) Acta Materallia, Vol 44, No 5, 1996, 1781-1792. The microstructures of MA TiNi-TiC and Ni-TX composite powders, prepared from elemental powders, were investigated. The powder was found to granulate to 3 to 10 mm after 3.5 hours MA. This is attributed to a melt-and-quench mechanism which was confirmed from the structures. Spherical TIC grains, with martensite and B2 structures were observed. It is suggested that self propagating synthesis occured initiated by heat of formation of Tic. ALLOYING ENERGY

PROCESS BALL MILLING

C. Kun et al. (Huazhong University of Science and Technology, Wuhan, China.) PM Technology, Vol 14, No 1, 1996, 2-7. In Chinese. MA of Fe and Ni powders in Ar was investigated with regard to microstructure and microhardness. Alloying is reported to be complete in 3 hours and the structure to be a mixture of body- and face-centred cubic phases. Further milling converted bee to fee. PROPERTIES COMPOSITES

OF ALIJMINIUM WITH SILICON

CARBIDE

S. Ryu et al. (Nihon University, Naraahino, Japan.) J. Japan Inst. of Metals, Vol 60, No 2, 1996, 231-237. (In Japanese.) It is reported that AI-Sic composites, reinforced with particles or particles and whiskers, had been made. Sic, was incorporated by MA and SiC,,, was added by PM processing. Structures and properties were investigated. Both types of Sic were uniformly distributed. Sic, increased strength which was further

36

MECHANICAL PROPERTIES ACRYLIC BASED INJECTION MOULDING FEEDSTOCKS

I.H. Moon et al. (Hanyang University, Seoul, Korea.) J. Japan Sot. Powder and Powder Vol 42, No 3, 1995, 347-352. Metallurgy, (In English.) CIP is reported to have been used to increase the density of debound MIM parts. The parts were enclosed in a rubber membrane and CIP at 550 MPa. Sintered density was increased.

OF

J. Valencia et al. (Concurrent Technologies carp, USA) Acrylic baaed binders were reported to have been used in #ceramic processing. These were shown to have high green strength, to give clean burnout and to be insensitive to humidity. Recent developments were described. Mechanical properties of parts made using the new binders were reviewed.

alloying

STRUCTURE OF MECHANICALLY ALLOYED NICKEL AND TITANIUMNICKEL/TITANIUM CARBIDE COMPOSITES

MECHANICAL DURING HIGH

moulding

COLD :ISOSTATIC PRESSING OF DEBOUND INJECTION MOULDED PART FOR IMPROVED PERFORMANCE

P. Perez et al. Mater. Charact., Vol 33, No 4, 1994, 349-356. Production of Nb& doped with B, Tom RS powder by HIP is reported. Powder and consolidated material were characterized. The powder had a fine two-phase microstructure with dendrites of NiAl. The consolidated alloy was single phase.

Mechanical

injection

kneading extruder was described. This is a single stage continuous process. Examples were given, including ceramics and hardmetals.

MPR January

1997

DEVELOPMENT OF NEW BINDER SYSTEMS WITH IMPROVED PROPERTIES FOR POWDER INJECTION MOULDING

EFFECTSOFFEEDSTOCK CHARACTERISTICS AND MOULDING CONDITIONS ON A DEFECT

R. Miura Muroran,

et al. (Japan Steel Works Ltd, Japan.) J.Japan Sot. Powder and Vol 42, No 3, 1995, Powder Metallurgy, 367-372. (In Japanese.) Defects in MIM parts were discussed with regard to factors involved and difficulty in predicting incidence of defects. The paper describes one defect, a crack in a thin walled part. Studies of process parameters, to eliminate the defect, are described.

PM components GEAR FUNDAMENTALS PM GEARS

- A GUIDE

TO

G. Shturtz. Gear Technology, Vol 12, No 5, 1995, 2828. The role of PM in manufacture of gear compon.ents is discussed with regard to alternat.ive methods, cost effectiveness of PM and ready availability of a wide range of metals and alloy powders. Customized mixtures for a variety of ferrous and nonferrous materials, leading to specific mechanical properties are noted.

1996 WORLD CONGRESS ON POWDER METALLURGY. The abstracts which follow are from papers which were presented at the Congress, which was held in Washington, D.C, USA, in June 1996.

Metal

injection

moulding

COMPOUNDING OF POWDER INJECTION MOULDING FEEDSTOCKS

P. Rieg. (Draiswerke, GmbH., Germany.) Machinery for preparing injection moulding feedstocks was discussed with regard to efficiency and economics. A

M. Youseffi, IA Menzies. (Loughborough University of Technology, Loughborough, UK.) The development ‘of two new binder systems, with better moulding characteristics and which allow higher powder loadings, was described. One binder is baaed on a thermoplastic, wax plasticiser and lubricant. The other is a water baaed gelling binder, gelling agent and lubricant. Applications to ceramics, FeNi alloys, stainless steels and hardmetals were discussed.

lsostatic

pressing

LARGE SIZE SUPERALLOY HIP ONLY

DISCS MADE FROM POWDERS BY DIRECT

G.S. Genrikh. (Al-Russian Inst of Light Alloys, Russia.) It was suggested that aerospace superalloy discs, !300 to 1150 mm diameter and 300 kg, could be made by HIP, subject to furthser developments in degassing and press technologies. The alloy considered was reported to have a tensile strength of 1600 MPa and a 100 hour rupture strength at 6510°C of 1100 MPa. EFFECT OF HIP PROCESS VARIATIONS ON QUALITY OF NICKEL ALLOY DISCS

L.V. Buslavsky et al. (All-Russian Inst of Light Alloys, Russia.) Investigations of the use of flow charts, heating to temperature followed by application of pressure, were described. Forming of a part and changes in structure and properties were studied for combinations of temperature and pressure. It was suggested that using a flow chart and preliminaxy heating allcowed development of a more uniform structure in a superalloy than simultaneous application of heat and