Ignacio Garrido

Surface Roughness Minimization in Turning PEEK-CF30 Composites with TiN Cutting Tools Using Particle Swarm Optimization

Poly ether ether ketone (PEEK) composite belongs to a group of high performance thermoplastic polymers and the addition of carbon fibers increases the resistance and rigidity of PEEK. Due to favorable mechanical and thermal properties and potential applications in various manufacturing industries, it is essential to analyze the machining performance of reinforced PEEK composites. The surface roughness is a widely used measure of product quality that could influence the performance of mechanical products and production costs. The present study establishes the relationships between the cutting conditions (cutting speed and feed rate) and three surface roughness parameters (centerline average surface roughness, maximum peak to valley height and root mean square roughness) by developing second order mathematical models based on response surface methodology (RSM). The reinforced PEEK with 30% of carbon fiber (PEEK-CF30) workpieces were machined using TiN-cutting tools. The experiments have been planned as per full factorial design of experiments (FFD). The developed surface roughness models were then employed with particle swarm optimization (PSO) to optimize the cutting conditions. PSO program gives the minimum values of surface roughness parameters and the corresponding optimal cutting conditions.

Investigating the deformation and damage scenario under tensile loading of ductile specimens using thermography

Abstract Mechanical properties of ductile materials are very sensitive to environmental conditions in particular temperature. The paper shows the results obtained in the simultaneous testing of 5182 H111 Aluminium alloy, S275JR Carbon Steel and F114 Carbon Steel specimens using conventional methods and thermography. The infrared thermography was used to quantify deformation localization zones, also to relate the temperature changes of the specimens, continuously recorded by thermography, with the load extension diagram. It enables to predict reaching the critical stresses which cause the appearance of fractures and to define the criteria for determining the maximum sample temperature alteration in the field of elastic and elastic-plastic strains. Infrared thermography was found to be an efficient tool for investigating the deformation and damage scenario under tensile loading.