High-strength discontinuosly-reinforced titanium matrix composites and method for manufacturing the same

Abstract

The method for manufacturing high-strength discontinuously-reinforced titanium matrix composite comprises the following steps: (a) preparing a basic powdered blend containing the matrix alloy or titanium powders having a particle size <250 μm for 95% of the powder and powders, which reinforcing matrix during high-temperature operations, such as blended elemental reinforcing powders, ceramic powders, intermetallic powders, and / or powders of complex carbide- and / or boride particles that are at least partially soluble in the matrix, (b) preparing reinforcing powders by co-attrition, mechanical alloying, or pre-sintering of blended elemental powders with each other and graphite, (c) mixing the basic powdered blend with the Al-V master alloy powder, and co-attrited, mechanically-alloyed powders, and pre-sintered powders in the predetermined ratio to obtain a chemical composition of titanium matrix composite material, (d) compacting the powder mixture at room temperature by any of room temperature consolidation process, (e) sintering at the temperature providing at least partial dissolution of dispersing ceramic and / or intermetallic powders, (f) high-temperature deformation at the temperature range of 1500-2300° F. resulting in additional in-situ formation of re-enforced particulates, and (g) cooling.

Description

[0001]The present application is a Divisional Application of U.S. application Ser. No 11 / 890,644 filed on Aug. 7, 2007, the entire contents of which is incorporated herein by reference.FIELD OF THE INVENTION[0002]The present invention relates to sintered titanium metal matrix composites discontinuously-reinforced with dispersed ceramic and intermetallic particles such as silicon carbide, titanium borides, vanadium carbides, titanium aluminides, etc.BACKGROUND OF THE INVENTION[0003]Titanium-based or titanium alloy-based metal matrix composites (TMMC) are of particularly great interest in the following areas: the aerospace and automotive industries. medical implants, armor, and chemical-resistant applications due to their high specific strength, high stiffness, low weight, and relatively high wear resistance. The titanium or titanium alloy matrix in these composites are reinforced by fibers or particles which have a substantially higher hardness and elastic modulus than the matrix all...

AI Technical Summary

Benefits of technology

[0014]It is therefore, an object of the invention is to produce a fully-dense, essentially uniform structure of flat and shaped titanium metal matrix composite consisting of high-strength and ductile matrix with uniformly distributed re-enforcing particles of controlled particle size that provides improved mechanical characteristics such as fracture toughness. flexure strength, impact strength, elastic modulus, and wear resistance.

[0015]Another object of this invention is to avoid interconnected porosity and manufacture the sintered composite material which may have only closed porosity and near full density after sintering, e.g., over 98% of the theoretical value.

Problems solved by technology

While the use of a number of manufacturing processes including sintering and hot deformation has previously been contemplated in the titanium matrix composite industry, as mentioned above, the processing limitations related to an ability to manufacture a near full density composite structure by low cost room-temperature consolidation, limited process stability, inability to manufacture the components with controlled sizes when components with close tolerances are being produced, high production costs, defective microstructure, porosity, and insufficient mechanical properties of not fully dense TMMC articles, established a need for development of the new low cost manufacturing processes for producing the TMMC with optimized mechanical properties and improved performance.