Aluminum-silicon alloys, cylinder blocks and bores, and method of making same

A method of producing aluminum-silicon alloys comprising forming a molten alloy consisting essentially of aluminum and an amount of silicon which is in excess of 12.7% and up to 18%, solidifying said molten alloy while controlling the growth rate of the solid phase during solidification at 200 or more microns per second and controlling the temperature gradient existing in the liquid phase at the solid/liquid interface during solidification at 100.degree. C/cm to produce in the solidified alloy a microstructure which is free of primary aluminum and silicon phases and is composed of fibrous, fully modified particles of eutectic silicon having a particle size of less than 10 microns.

A method of producing aluminum-silicon alloys comprising forming a molten alloy consisting essentially of aluminum, an amount of silicon which is in excess of 12.7% and up to 18%, and up to 0.1% strontium, and solidifying said alloy under conditions of growth rate and temperature gradient which are sufficient to produce a microstructure in the solidified alloy which is free of primary aluminum and silicon phases and is composed of fibrous, fully modified particles of eutectic silicon having a particle size of less than 10 microns, said growth rate being 200 or more microns per second, said temperature gradient being 100.degree. C/cm, and said amount of strontium being sufficient, in combination with said silicon content, growth rate and temperature gradient, to assist in the production of said microstructure.

A method of producing aluminum-silicon alloy comprising forming a molten alloy consisting essentially of aluminum and about 13 to about 18% by weight of silicon, and solidifying said molten alloy in a directional solidification furnace under conditions of growth rate and temperature gradient which are sufficient to produce a microstructure in the solidified alloy which is free of primary aluminum and silicon phases and is composed of fibrous, fully modified particles of eutectic silicon having a particle size of less than 10 microns, said growth rate being controlled during solidification in the range of 200 to 2,000 microns per second and said temperature gradient in the liquid phase at the solid/liquid interface being controlled during solidification in the range of 10.degree. to 150.degree. C/cm.

A method of producing aluminum-silicon alloy comprising forming a molten alloy consisting essentially of aluminum, about 13 to about 18% by weight of silicon, and up to 0.1% strontium, and solidifying said alloy in a directional solidification furnace under conditions of growth rate and temperature gradient which are sufficient to produce a microstructure in the solidified alloy which is free of primary aluminum and silicon phases and is composed of fibrous, fully modified particles of eutectic silicon having a particle size of less than 10 microns, said growth rate being controlled during solidification in the range of 200 to 2,000 microns per second and said temperature gradient in the liquid phase at the solid/liquid interface being controlled during solidification in the range of 10.degree. to 150.degree. C/cm.