Produção e caracterização de compósitos de titânio-grafeno a partir de pastas para impressão 3D por extrusão.

Abstract

Additive Manufacturing (AM), also known as 3D printing, represents a revolutionary technology that has significantly altered the industrial landscape over the years and has a transformative impact on various sectors. It provides a flexible and innovative approach to the production of parts and products with complex geometries. One of the possible processes for metal manufacturing is 3D printing by paste extrusion. The process is derived from the technique of ceramic printing by paste extrusion. This technique involves using a paste composed of a mixture of metal powders and binders. The paste is then printed using the extrusion process, resulting in a green part that undergoes subsequent sintering. The success of 3D printing by paste extrusion is contingent upon the flow properties of the paste, the strength of the green component, and the sintering procedure. This AM process holds promise for the manufacturing of metal matrix composites. Among metal matrix composites, titanium-graphene composites stand out. Titanium-graphene composites represent an advanced class of materials that combine the exceptional properties of titanium and graphene. This combination offers notable advantages in terms of mechanical strength, lightness, electrical conductivity, and corrosion resistance, making these materials promising for a variety of applications. In this study, AM of titanium-graphene composites was carried out through the compaction of metal pastes followed by sintering. Three compositions of titanium and titanium-graphene pastes were produced using polyvinyl alcohol (PVA) as a binder. Green samples were produced by cold compaction of pastes for 3D extrusion and then subjected to thermal binder extraction and sintering. The sintered samples were characterized for microstructural, mechanical, and porosity properties. The results obtained from samples manufactured by cold compaction of titanium-graphene pastes indicated that the addition of graphene improves hardness. With the addition of 0.3% by weight of graphene, an increase of over 71% in microhardness and over 17% in the modulus of elasticity was achieved. The addition of 0.5% graphene showed a embrittling effect, reducing compressive strength and microhardness due to higher porosity values. The results suggest that graphene can be efficiently used as a reinforcement for titanium alloys when added in an appropriate proportion.