Fatigue performance of additive manufactured TiAl6V4 using electron and laser beam melting

Increasingly, additive manufacturing is considered to reduce weight and lead time of aerospace components. Despite the high potential of this manufacturing technology, reliable mechanical properties are an essential prerequisite for future series production. Therefore, the aim of this work was to contribute to an improved understanding of the factors influencing the mechanical properties of laser powder bed and electron beam melted TiAl6V4. Therefore, tensile tests, fracture toughness tests, fatigue crack growth measurements for different r-ratios as well as high cycle fatigue properties were determined for different surface roughness and heat treatments

Effect of surface roughness on fatigue performance of additive manufactured Ti–6Al–4V

Additive manufacturing is increasingly considered for production of high quality, metallic, aerospace parts. Despite the high potential of this manufacturing process to reduce weight and lead time, the fundamental understanding of additive manufactured Ti–6Al–4V material is still at an early stage, especially in the area of fatigue and damage tolerance. This paper covers the effects of inherent surface roughness on the fatigue life. In the as built condition, metallic parts have a poor surface texture, which is generally removed in fatigue critical areas. It is shown that the fatigue properties of Ti–6Al–4V samples, produced by direct metal laser sintering and electron beam melting, are dominated by surface roughness effects. A simple model based on an equivalent initial flaw size is formulated

Mechanical properties of Ti-6Al-4V fabricated by electron beam melting

Powder bed additive manufacturing of titanium components offers several advantages. The high freedom of design enables the fabrication of structurally optimized, lightweight parts. Complex geometries may serve additional functions. The use of additive manufacturing has the potential to revolutionize logistics by dramatically reducing lead time and enabling a high degree of customization. Manufacturing near net shape parts reduces the loss of expensive material.For the application in safety relevant parts certainty about static and fatigue strength is critical. A challenge arises from complex influences of built parameters, heat treatments and surface quality. Ti-6Al-4V specimen built by electron beam melting (EBM) were subjected to heat treatments adapted to various employment scenarios. The results of tensile and fatigue testing as well as crack propagation and fractography will be compared to titanium manufactured conventionally and by selective laser melting (SLM). The mechanical behavior will be correlated to the microstructural evolution caused by the heat treatments