thermal stabilities were evaluated. Reaction products at matrix/reinforcement interfaces were considered. DENSIFICATION OF POROUS ALUMINIUM MATRIX COMPOSITES MADE BY REACTIVE SINTERING
L.Froyen, CFeng. (Catholic University, Leuven, Belgium.) It was noted that metal matrix composites made by reaction synthesis are often porous and require further densification. Structures and properties of Al(TiB,, A&O,) composites were investigated after densification. Hot pressed Al-10.2vol%Al,O,-9.2TiBs was well densified and had a bend strength of 509 MPa. Squeeze cast composite, in which Al was infiltrated under pressure, did not attain as high a value due to poor matrix/reinforcement bonding. FABRICATION OF TITANIUM MATRIX COMPOSITE REINFORCED WITH CHOPPED ALUMINA FIBRES
A.Kamiya, K.Naganuma. (National Industrial Research Inst., Nagoya, Japan.) Ti matrix composites were reviewed with reference to properties attained with SIC and Also, fibres. Composites with SIC gave better results. An investigation of Al-Also, (fibre) was described.
Composites were hot pressed from Ti powders and chopped fibre and processed so as to avoid degradation of the fibre. Structures and properties were described. EFFECTS OF MICROSTRUCTURES MECHANICAL PROPERTIES OF MULTI-PHASE SYSTEMS
H.Acciari et al. (Inst. de Quinica, Araraquara, Brazil.) Ag base alloy powders and dental amalgams were characterized for composition and structure. The amalgams were found to be porous materials consisting of residual Ag alloy particles and reaction products with Hg. Properties were shown to depend on a wide range of factors,
MAGNETIC PROPERTIES OF CORES MADE FROM IRON POWDER WITH INORGANIC INSULATING COATING
M.Hiroyuki et al. (Kobe Steel Ltd, Hyougo, Japan.) Maintenance of high flux density and reduction of core losses in magnetic parts, at high frequencies, was discussed with regard to eddy currents. It was noted that resin bonded Fe powders may not have sufficient saturation flux density and the resin may not withstand operating temperatures. Development of Fe powders, with inorganic insulating coatings, was reported. These were shown to perform satisfactorily. CHANGE DURING
REACTIVE SINTERING OF SOFT IRON-COBALT MAGNETIC PARTS
P.Weston (University of J.Wood, Nottingham, UK.) It was reported that elemental Fe-Co powders, with small amounts of Al, had been hot pressed and sintered at 1150°C to study the effects of the Al additions. The Al gives a reaction sintering effect and results in greater homogeneity and lower porosity.
The Slot heater
fitted to all press types.
50 MPR May 2000
and can be
clean metal powders for:
MIM ?? magnetic alloys ?? hydrogen storage ??
RSP Properties thick film pastes ?? plasma/HVOF
low oxygen metal matrix ?? dental alloys
R&D facility ?? trial batches ?? alloy design
Melt spinners CVIKVD systems ?? Melt extractors ?? Arc melters ?? Thermal engineering
M.G.Yoo et al. (Korea Inst. of Science and Technology, Seoul, Korea.) An investigation of structural changes, notably in porosity, arising from infiltration of Cu, at 1150°C for 2 hours, into a W skeleton with 34% porosity was described. Factors limiting homogenization of the structure were discussed. It was concluded that isostatic and capillary effects are important.
OF MICROSTRUCTURE INFILTRATION