| 摘要 |
PURPOSE:To obtain the lightweight low expansion composite material having practical strength and manufacturable with good workability by forming the composite material of a uniformly and dispersedly mixed system constituted of spheroidal glass balloons having specified grain size and a light alloy and regulating its specific gravity and thermal expansion coefficient into specified ones. CONSTITUTION:The lightweight low expansion composite material is formed of a uniformly and dispersedly mixed system constituted of glass balloons having 50 to 200mum grain size range and >=90% spheroidizing rate and a light alloy such as an A390 alloy and has <=1.8 specific gravity and <=16X10<-6>/ deg.C thermal expansion coefficient. In the composite material, sufficient lightening in weight and low expansibility can be attained in the range of strength applicable to practical use, and its workability at the time of manufacturing is furthermore excellent. As the above glass balloons, classified fly ash, etc., are used. The composite material can be obtd., e.g. by sufficiently filling the glass balloons into a die preheated to about 400 deg.C, pouring the molten metal of the light alloy thereto and executing pressure forming. |
