Comalco Aluminium Limited

The University of Melbourne

Kenong Xia

Raymond Walter Shaw

Christopher J Heathcock

Leslie C Edwards

Thomas K Smith

Malcolm J Couper

Gabriela Tausig

A process for producing a shaped metallic article includes the steps of melting a metal alloy, reducing the temperature of the molten metal to the liquidus temperature, casting the molten metal at the liquidus temperature into a mould and solidifying the molten metal to obtain a feedstock material. The feedstock material is subsequently heated to a temperature between the liquidus and solidus temperatures to produce a self-supporting thixotropic material which is then formed to the desired shape. Casting the feedstock material from a melt at substantially the liquidus temperature produces a microstructure that is especially suitable for subsequent forming of the thixotropic material and this allows use of slower forming speeds and lower forming pressure during the forming step.

Semi-solid metal processing

A calcined microsphere of ultrafine bauxite particles having a mean particle size in the range 0.01 to 0.3 micrometers, said microsphere having a particle size less than 30 micrometers and being characterized by a substantially solid form having a pycnometric density substantially falling in the range 3.2-3.0 g/cm.sup.3, a BET surface area substantially falling in the range 0.05 to 0.5 m.sup.2 /g and a crystal grain size less than 4 micrometers, the surface chemistry of the microsphere being modified to enhance the wettability of the microsphere and to improve its ability to bond strongly with matrix materials in use.

Method of making ceramic microspheres

A calcined microsphere of ultrafine bauxite particles having a mean particle size in the range 0.01 to 0.3 micrometers, said microsphere having a particle size less than 30 micrometers and being characterized by a substantially solid form having a pycnometric density substantially falling in the range 3.2-3.9 g/cm.sup.3, a BET surface area substantially falling in the range 0.05 to 0.5 m.sup.2 /g and a crystal grain size less than 4 micrometers, the surface chemistry of the microsphere being modified to enhance the wettability of the microsphere and to improve its ability to bond strongly with matrix materials in use.

Ceramic Microspheres

Growing community of inventors

Mitcham, Australia

Kenong Xia