Production and properties of sintered alloys were discussed with reference to formation of intermetallic compounds and precipitation hardening. It was considered that high energy ball milling was the best way of preparing homogeneous alloy powder followed by reactive sintering, extrusion and heat treatment. A Cu4wtXTi alloy was shown to have a strength of 900 MPa with 15% elongation and good electrical conductivity. Addition of graphite to form TIC was considered.
Applications of metal fibres and fabrication by PM techniques were discussed. Fibres as small as 1 pm in diameter can be used in conjunction with other metals, powdered or molten, ceramics or polymers to make filter media, conductive plastics, toughened ceramics etc with a wide range of properties.
TiC enhanced the replacement of M& carbides by MC only in the presence of V. NbC formed MC carbides but did not encourage the replacement of M&. A complex carbo-sulphide phase formed between Tic and MnS.
and FeB were described. Cu coated M2 powder were blended with FeB and cold pressed and vacuum graphite, sintered. The objectives were the attainment of near net shape and good wear properties. Variations in composition and process conditions were studied.
Porosity and porous materials PRODUCTION
POROUS BY POWDER
Inst. for Applied
Materials Research, Bremen, Germany) The ability of PM to produce highly porous parts was discussed with reference to the needs of transport industries for light weight materials which may be met by hollow sphere structures and metallic foams. New technology was said to be needed for processing fibres into, for example,
and for catalytic
EFFECT OF PROCESS CONDITIONS ION NITRIDED SINTERED IRONMOLYBDENUM ALLOYS
that a new PM technique
said to be presented.
TECHNOLOGIQUES L. Brndusan.
of the wire used
support and on the wires. Strength
the spacing decreased as
University, Rostow-on-Don, Russia) Experiences in the production
of thin in in
machinery, were discussed. for rapid densification were
outlined. The technique was shown to have advantage over extrusion in not a binder.
in the oxidised
Continuously to have was not
STEEL K-H. Lindner,
were investigated. and temperature
wall PM tubes, with a density gradient the radial direction, for use as filters hydraulic Schemes
steam treated by proceedures,
processing was shown to be cheaper. Quality control methods were outlined.
1120 et al
fracture, of a diffusion alloyed 4%Ni1.5%Cu-0.5%Mo-0.6%C steel, sintered at
was considered to be industrial mass production. 1250°C was recommended of stressed
too long for 30 minutes at for manufacture
ON FATIGUE SINTERED
Vienna, Austria) The effect of
LAYER ON SINTERED
LOW ALLOY STEELS
EFFECT OF SILICON MANGANESE AND NICKEL ON PLASMA NITRIDED STEELS
polis, Brazil) It was reported
transient liquid phase sintering. The fatigue
and the size of secondary that
strength for up to 2x10s cycles at R=-1 the threshold
was found to increase nitrided
layer and N penetration
A.N. Klein et al (LABMAT/UFSC,
Ni steels in order to determine the effect of each element on nitride layer formation. Si
R. de Bruyne.
better microstructural homogeneity and improved pore shape. 120 minutes
had been carried out on sintered Si, Mn and REVISITED
for the steels
but with differences
Mechanical IRON BASED
of CH4 was described.
treated materials were reported better quality and ferric oxide
on the diameter
Cluj-Napoca, Romania) (In French). It was reported that a reinforced porous
for the between
of Genoa, Genoa,
Trento, Italy) Sintered Fe specimens,
with small amounts attained
Service performances (Fraunhofer
20% or less. Structures were cellular. Property data was
METALLURGY H.D. Kunze.
Metallurgy, Krakow, Poland) Investigation to optimise processing of M2 high speed steels with additions of Cu
Italy) An investigation of ion nitriding, at 59O”C, of Fe-l.S%Mo at densities of 7.0 and 7.5gm.cme3 and different N:H ratios
material had been obtained by sintering a spherical powder on a square cell metallic textured support and using intermittent
OPTIMIZATION OF LIQUID PHASE SINTERING OF M2 HIGH SPEED STEELS WITH BORON AND COPPER Cias
had been developed for the production metallic foams with relative densities
Bradford, Bradford, UK) It was reported that HSS matrix composites with TiC or NbC particles and MnS had been sintered to full density. Microstructural changes were described.
many) It was reported
CERAMIC AND SOLID LUBRICANT PARTICLES IN HIGH SPEED STEELS J.D.
and promoted of the diffusion
E. Stagno et al (University SELECTED
increased hardness homogeneous hardening
crack growth were determined. A Kitagawa diagram was used to predict tolerable defect
sizes and to estimate
as a function
of pore size.