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US 4,450,136 AGranted
Calcium/aluminum alloys and process for their preparation
AssigneePfizer Inc.
InventorsDavid M. Dudek, Mark A. Lambert
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AssigneePfizer Inc.
InventorsDavid M. Dudek, Mark A. Lambert
Estimating the term…
A substantially homogeneous calcium/aluminum alloy having a calcium/aluminum atomic ratio of from about 60/40 to 80/20 and with useful and unexpected properties of brittleness, passivity to atmospheric moisture and low volatility is prepared by a process which comprises adding aluminum under an inert atmosphere to molten calcium at a temperature of from about 550.degree. to 1100.degree. C. and at a rate to prevent substantial solids formation in the melt during the addition. The molten alloy is converted to particulate solid either by melt atomization or by casting, crushing and grinding. Lead/calcium/aluminum and tin/calcium/aluminum alloys are prepared by adding the calcium/aluminum alloy to the molten lead or tin, while calcium/aluminum/lithium alloy is prepared by adding lithium to the molten calcium/aluminum alloy.
A process for the preparation of a substantially homogeneous passive calcium/aluminum alloy having a calcium/aluminum atomic ratio of from about 60/40 to 80/20, which comprises adding elemental aluminum to molten elemental calcium under an inert atmosphere to obtain a melt of a desired composition, the temperature of said melt during said addition being maintained at from about 550.degree. to 1100.degree. C., said aluminum being added at a rate to prevent substantial solids formation in said melt during said addition.
Solid calcium/aluminum alloy having a calcium/aluminum atomic ratio of from about 60/40 to 80/20, said alloy being brittle, relatively nonvolatile and essentially nonreactive to atmospheric moisture.
Dependencies are inferred from the claim text.