چكيده به لاتين
Additive Manufacturing (AM) is a material processing which enables fabrication of complex geometries, which are difficult or impossible to build using traditional manufacturing techniques. selective Laser Melting (SLM) is a laser additive manufacturing process where parts are additively manufactured using laser melted powder material. Several process parameters such as laser power, beam diameter, scanning speed and the hatch spacing are amongst the important parameters which could directly influence the SLM material microstructure, porosity rate and, therefore, mechanical properties. Similar to most other components in different industries, AM parts typically undergo cyclic loadings through their service life. Therefore, understanding their fatigue behaviour is essential to be able to widely adopt the technique in different industries while preventing fatigue failures. Ultrasonic fatigue testing is an effective tool to carry out high and very high cycle fatigue (VHCF) tests. Due to the extremely high loading frequency of 20 kHz, ultrasonic fatigue loading considerably reduces the testing time. This project is intended to study the fatigue behaviour of a laser additive manufactured Ti-6AL-4V alloy under cyclic tension-compression at 20-kHz frequency. The main objective is to assess the effect of some fabrication process parameters, on the microstructure and fatigue properties of the material using ultrasonic fatigue testing. Application of ultrasonic fatigue machine would enable a rapid investigation of the additive manufacturing process parameters on the material fatigue performance. Keywords: Additive manufacturing, selective laser melting, Ti-6AL-4V alloy, very high cycle fatigue, Ultrasonic fatigue testing.
