Patent ID: 6658715
Filing Date: 2003-12-09
Classification: B22F,C22C,Y10T

Abstract:
A method of producing an element of composite material (1) comprising a metal matrix and a reinforcing structure, said method comprising the steps of:forming a first distribution of first elements (20) defining said matrix; forming a second distribution of second elements (21) defining said reinforcing structure; and compacting said first and second elements (20, 21) to obtain a distribution of said reinforcing structure inside said matrix; wherein said first elements are metal wires (20); and said step of forming said first distribution comprises the step of assigning each said second element (21) an orderly distribution of said metal wires (20) such that that said metal wires surround said second elements and each second element is separated from all other second elements by said metal wires and said second elements will be surrounded by said metal matrix as a composite therewith in which the second elements of said reinforcing structure will be spaced from one another, wherein said second elements are reinforcing fibers, wherein said assigning step comprises the step of preparing a woven element (16) by placing at least one said metalwire (20) alongside each said reinforcing fiber (21), wherein said metal wires (20) and said reinforcing fibers (21) are annular and said woven element forms a ring; and said step of preparing said woven element (16) is performed by placing said metal wires (20) and said reinforcing fibers (21) about a toroidal main body (7) made of metal material, further comprising the step of forming a base structure (6) by fitting covering means (23, 24, 25) of metal material onto said main body (7) to close said woven element ring (16) between said main body (7) and the covering means (23, 24, 25), wherein said main body, (7) and said covering means (23, 24, 25) define, at the end of said compacting step, respective peripheral portions of said element of composite material (1); and said woven element ring (16) defines, at the end of said compacting step, a core of said element of composite material (1), wherein said compacting step comprises the steps of: placing said base structure (6) in an environment of controllable temperature and pressure conditions; heating said environment so as to bring said metal wires (20), said main body (7) and said covering means (23, 24, 25) uniformly to a superplasticity temperature and applying a first pressure thereto to axially compact said woven element ring to fill the gaps between the individual wires and the fibers in a first compaction step; and thereafter applying a pressure higher than the first pressure to compact the structure in all directions to collapse and bond together the axially compacted woven element ring (16) said main body (7) and said covering means (23, 24, 25).