In the present study, in addition to reviewing the severe plastic deformation (SPD) processes and their mechanisms in the microstructural evolution, previous researches on the corrosion behavior of various metallic materials that have undergone SPD are investigated. Grain size, as an important metallurgical parameter, affects a broad range of mechanical, chemical, physical and electrochemical properties of metallic materials. As mostly reported, the reduction in grain size is in line with a considerable improvement in the mentioned properties. In recent years, SPD methods have been nominated as an ideal way to reach nano- and ultrafine-grains. Among the mentioned properties, the corrosion performance of ultrafine-grained materials produced by SPD methods is still controversial for researchers. The purpose of this study is to review the SPD methods, the mechanism of grain refinement during them, and their effects on the corrosion behavior of various metals and engineering alloys such as steels, aluminum, titanium, copper, and magnesium.

Propagation and dispersion of acoustic waves is one of the important phenomena in physics. Acoustic-waves are nowadays widely used in a variety of applications ranging from underwater communications, identification and specification of the internal defects of materials to extracorporeal shock wave lithotripsy. Apart from application and utilization of such phenomena, study on production and propagation of acoustic waves have a special importance. This paper is focused on the experimental and the analytical investigation of acoustic-waves loss in metallic materials. Firstly, the governing differential equations of the acoustic waves propagation are derived and solved for a damped cylindrically shaped rod. With regard to boundary and initial conditions, the equation and the curve of damped acoustic wave displacement are obtained. By using experimental modal techniques, experimental investigations on the energy loss and the extraction of damping coefficients of acoustic waves are done. The experimental information obtained from experimental tests such as Frequency Response Function, the formula and the curve of the energy loss versus frequency are extracted. Selected metallic materials for the experimental set-ups are two specimens of steel and aluminum.

Friction stir processing is a solid state process to modify microstructure and mechanical properties of sheet metals and as-cast materials. In this process stirring action of the tool causes the material to intense plastic deformation that yields a dynamical recrystallization. In this study the effect of FSP and process parameters on hardness, and microstructure ofAl5083 has been investigated. Also by using of FSP, composite layer of TiO2/Al5083 has been produced. Results show that, FSP leads to finer and homogenized grain structure, as well as increased hardness, strength, toughness, and elongation of material. The composites produced by FSP have uniformly distribution of TiO2 particles between the grains of base metal.

There are different types of suspended metal materials in wastewater and municipal water, and high-cost coagulants must be used to remove them in water refinery. polyaluminum chloride (PAC) is one of the newest coagulants. Due to the high cost and long preparation time of PAC, it is more economical to use simulation methods instead of experimental tests. In this paper, the adsorption process of copper, zinc and cadmium on PAC coagulants has been studied using the density functional theory (DFT) by Quantum Espresso calculation code. The calculations are based on the flat wave method with quasi-potential using the generalized gradient approximation (GGA). The pseudopotential used is also generated by the ultra-soft method. Analysis of the band structure and density of electron states showed that the PAC materals are semiconductor with an energy gap of 5.4 eV. Also, the results obtained from adsorption calculations showed that copper, zinc and cadmium metals are adsorbed with PAC coagulant adsorption energy of -4.56, -8.79 and -13.25, respectively. According to these results, increasing the conductivity of the PAC compound, which is the result of reducing the energy gap during the adsorption process, can be a factor in identifying suspended metals in water.

A 38 years old man with ASA class1, weight 65 Kg, height 170 cm that admit for inguinal herniation elective surgery in Hamadan Shahid Beheshti Hospital. In preop. Visit he had no history of diseases and drug and he was stable. He was in mallampati class 2. He disagrees with spinal anesthesia and we decided to general anesthesia. He had unexpected difficult tracheal intubation and Therefor we used a metal guide instrument for intubation in the first effort. After secure endotracheal tube the operation was beginning and last for 1 hour. At the recovery patient had sever cough and bloody secretion, of course level of consciousness was good. At that time and during coughing, suddenly one pieces shot out from mouth and as soon as respiratory symptom diminished. After study of that material we notice that it is a part of metal guide that separate from it. It is an important experiment that must to use only standard material. Fortunately the patient without any sequel and in good condition discharge from hospital.

Fiber metal laminates (FMLs) are one of the most widely used hybrid polymeric composites in the aerospace and marine industries that are fabricated using the bonding between the metallic and polymeric layers. The combination of the advantages of both metals and composites is the main reason for the usage of the FMLs. Due to the application of FMLs under different temperature conditions, in the present study, the Charpy impact behavior of smart FMLs in comparison to fiber metal laminate was investigated at temperatures of -45, +25 and 90 °C. FML samples were made of two layers of 6061-T6 aluminum alloy and four layers of glass fiber-reinforced epoxy (GFRE), which shape memory alloy (SMA) wires by zero and 5% pre-strain were placed in the middle layers. The investigated parameters in this study were the number of SMA wires, the pre-strain effect of SMA wires, and also the effect of temperature on the energy absorption values of the FMLs. The results showed that the presence of two SMA wires at temperatures of -45, +25 and + 90 °C respectively caused the increment in the energy absorption by 14, 20 and 8%, compared to the without SMA wire samples.

The growing interest in studies on ultrafine - grained metallic materials is motivated by attractive mechanical properties, such as high strength with sufficient ductility. In recent years, severe plastic deformation (SPD) techniques have gained importance because of production of ultrafine grain materials with outstanding new properties. Multi - directional forging (MDF) is one of SPD methods that assume the advantage of MDF in its high efficiency and low processing cost. In this paper the influence of annealing time regarding the microstructure and microhardness of ultrafine - grained low carbon steel produced by multi - directional forging was studied. Results show that with increasing time grain grows take place and microhardness decreases.

Insulated rail joints are one of the most important components of the railroad and their failure, deals a massive financial loss for our country. Usually, these joints are bearing different dynamic and quasi-static loads such as tensile load and bending moment. In this research, design and construction of insulated rail joints from composite material was examined, due to their optimized performance rather than conventional materials. The composite epoxy/glass fiber was chosen as a material for insulated rail joints, based on the failures accrued for conventional insulated rail joints. To evaluate the mechanical properties of composite samples, the tension, three point bending and hardness experiments were carried out based on ASTM standards. The results showed that the improvement of mechanical and flexural strength of composite insulated rail joints in comparison with conventional insulated rail joints. In addition, the estimated cost of composite insulated rail joints was decreased by 40 percent to European companies.

This paper presents the results of the experimental and analytical investigation carried out using a steel forged material، EA4T، subjected to impact loading conditions within the strain rate domain101-103 (1/s). The standard three point bend test specimens manufactured according to ASTM 399 standard were subjected to impact loadlevels correspondingto preset defined impact energy levels by applying the Izod impact testing equipment. The specimens were also modeled and the loading condition was simulated using the finite element commercial software، ABAQUS v6. 11. Both the experimental findings and the finite element analysis results indicated that the crack initiation conditions were satisfied when the impact energy applied to the specimen reached a specifiedlevel. It was found that for a lower level of applied impact energy، the impact loading resulted in improving the fatigue characteristic of the material. In contrast، application of the higher impact energy caused the crack to propagate further. The other finding of the study was that increasing the plastic zone size decreased the crack propagation rate (da/dE).