The effect of the heat treatment on the microsturucture and the mechanical response of a commercial Al–Zn–Mg–Cu alloy (AA7075) was studied. The influence of annealing on the hardening and plastic properties of Al–Zn-Mg–Cu alloy was investigated by indentation and tensile tests. The microstructural evolution of the alloy was examined by meant of optical, scanning and transmission electron microscopies. After various ageing states, the Al–Zn–Mg–Cu alloy showed significant changes in microstructure and mechanical behaviour. After quenching, the microstructure was characterized by high ductility. Following ageing at 140 °C, corresponding to the maximum hardness value, the alloy reveals a high volume fraction of small η′ precipitates. The minimum hardening is recorded after ageing at 350 °C. The radical change in the microstructure of the alloy influences its mechanical behaviour, especially in hardening and plasticity.

Replace lost teeth by artificial prosthetic has been a preoccupation since the dawn of human time. The aim of our work is to study mechanical behavior of the interaction distance between two dental implants, in order to serve as support for a crown, a bridge element or an attachment of the prosthesis.Our purpose is to make a comparative study of five models that is different only by the interaction distance between 0.5 mm and 2 mm spacing two implants, to clarify the mechanical behavior of this interaction distance. The used materials are the biomaterials which are intended to be in contact with biological systems. Modeling of dental implant and the various components is done using Solidworks.We studied the static mechanical behavior of the implant using numerical methods.

Microstructure, hardness and fracture toughness of low and high chromium high speed steel used in hot strip mills and subjected to conventional heat treatment have been examined. The influence of tempering temperatures on the mechanical properties of these products, determined using tensile and fracture toughness tests, was studied in this research work. The developed microstructures have been characterized by XRD, optical microscopy and SEM examinations. Macrohardness and microhardness of the specimens have been evaluated by Vickers indentation technique. The fracture toughness of these products was investigated using the rupture weight on 3 points bending specimens. The plane strain fracture toughness KIc and the fracture strength were measured for each alloy. The shell is high harness high speed steels, and the core is nodular cast iron. It was found that most fracture occurred in the eutectic carbides formed by the high content alloy element, such as Mo,V,Cr, but that for the alloys with a reduced volume fraction of eutectic carbides, a small amount of crack propagation occurred in the austenitic dendrites.

The assembly of different types of materials like metals and ceramics forms a structure called sandwich structure, which need advanced techniques to joint it together like the thermo compression. However, the rise of residual stress caused by the discontinuity of nature of this type of sandwich material, like incompatibility of the characteristics, which creates a risk of rupture of the structure and limited the using range of these types of materials. In this paper, we study the bonding of ceramic and metal and we will focus on the role played by the ceramic element in the stress state of ceramic/ metal interface and the stresses evaluation by Finite Element when the structure is subjected to thermo-Mechanical loading.

This work is part of an ambitious project aiming to manufacture epoxy-glass leaf spring by microwave processing. Physical properties of final products to be manufactured, in particular the mechanical properties, are directly dependent on uniform repartition of microwave source heating during the treatment. The major problem in microwave processing, however, is attenuation of microwave source. We propose Dielectric Effect of Attenuation Inversion of the Electromagnetic Waves (DEAI) as a new way for uniform treatment of epoxy glassmicrowave energy. This solution utilizes dielectric properties of the mold to control the microwave heat source attenuation into the composite to be treated. Electromagnetic modelling of microwave process was carried out and validated by experimental results. The results show that microwave source heating attenuation can be controlled and inversed. We demonstrated uniform treatment on epoxy-glass parts ca. 100 cm long by means of compensation of microwave source attenuation.