Chemistry and Adhesion at the Interface of Ti-CNT composites

Carbon nanotubes are promising candidates for the reinforcement of metals. The combination of Ti with carbon nanotube would results in a material combining high strength, low weight, a low coefficient of thermal expansion with good high temperature stability. Nevertheless to achieve this theoretically predicted properties, a comprehensive study of several aspects will be necessary including the selection of appropriate nanotube raw material, the dispersion of the nanotubes in the matrix as well as the tailoring of the interface between the metallic matrix and the reinforcement. A key problem to solve is to get a homogenous dispersion of nanotubes in the matrix. Homogenous dispersion can be achieved by various methods which will be investigated, e.g. using surfactants or by using plasma pre- treatment. An advanced method to achieve a composite material having a good dispersion of the nanotubes is the coating of nanotubes by either physical or chemical vapor deposition. Of course this is a challenging task and requires careful study and optimization of deposition/dispersion techniques. After identification of the most promising dispersion/coating solutions, composite materials will be prepared by different powder metallurgical approaches including processes such as hot isostatic pressing, hot pressing or rapid sintering techniques. It is already known that the sintering of titanium requires a careful control of processing conditions. Therefore an optimization of processing conditions is necessary in order to avoid oxidation or eventually severe reactions between the Ti matrix with the nanotubes. Besides a detailed study of the influence of various pretreatment/coating in combination with consolidation conditions on the interfacial reaction and adhesion properties, the mechanical and thermomechanical properties of this promising material system will be investigated. Of course a clear goal of the project will also be to identify possible applications for this type of material.

Carbon nanotubes are promising candidates for the reinforcement of metals. The combination of Ti with carbon nanotube would results in a material combining high strength, low weight, a low coefficient of thermal expansion with good high temperature stability. Nevertheless to achieve this theoretically predicted properties, a comprehensive study of several aspects will be necessary including the selection of appropriate nanotube raw material, the dispersion of the nanotubes in the matrix as well as the tailoring of the interface between the metallic matrix and the reinforcement. A key problem to solve is to get a homogenous dispersion of nanotubes in the matrix. Homogenous dispersion can be achieved by various methods which will be investigated, e.g. using surfactants or by using plasma pre-treatment. An advanced method to achieve a composite material having a good dispersion of the nanotubes is the coating of nanotubes by either physical or chemical vapor deposition. Of course this is a challenging task and requires careful study and optimization of deposition/dispersion techniques. After identification of the most promising dispersion/coating solutions, composite materials will be prepared by different powder metallurgical approaches including processes such as hot isostatic pressing, hot pressing or rapid sintering techniques. It is already known that the sintering of titanium requires a careful control of processing conditions. Therefore an optimization of processing conditions is necessary in order to avoid oxidation or eventually severe reactions between the Ti matrix with the nanotubes. Besides a detailed study of the influence of various pretreatment/coating in combination with consolidation conditions on the interfacial reaction and adhesion properties, the mechanical and thermomechanical properties of this promising material system will be investigated. Of course a clear goal of the project will also be to identify possible applications for this type of material.