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One of the most important problems that the components of the prosthetic limbs suffer from; the increase in walking speed leads to an increase in the ground reaction force. In this research, a new shank was design and manufactured using the porous functionally graded materials by a 3D printer of PLA material, and to ensure the success of this shank, several tests were conducted on it, including to know the mechanical properties, as well as the life test by a special device that was manufactured. A test was conducted to know the life of the shank when normal walking (about 1.35 m/sec) and running ( about 6 m / sec ) , and it was found that this shank that was successful and did not fail in that test, the prosthetic foot ( type SACH) failed before it at normal speed and high speed.

The influence of friction pressure on welding quality when friction stud welding 1017 low carbon steel with AISI 304 austenitic stainless steel is investigated in this study. friction stud welding is employed in industrial applications instead of conventional welding processes Due to the friction welding process didn't need to reach the melting point of welded metals. Welding is performed on these dissimilar metals by utilizing a lathe machine with a load cell connected to a weight indicator and a manufacturing grip to fasten the plate at a rotating speed of 1600 RPM, a friction time of 20 seconds, and a friction pressure of (15, 20, and 25) MPa. After the welding procedure is completed, the specimens are subjected to tensile, torque, and hardness tests to evaluate the welding quality. In addition, optical microscope research was carried out to determine the microstructural aspects. The effect of friction pressure on welding quality was investigated based on the information generated from the results. The increase of friction pressure during the process from 15 MPa to 25 MPa leads to an increasing ultimate tensile strength from 203 MPa to 210 MPa approximately. Also, the torque values raised from 179 N.m to 198 N.m in the same case.

In this research an analysis for improving the fatigue behavior (safety factor of fatigue) of non- articular prosthetic foot (SACH) in the region (Bolt Adapter).The laser peening was carried to the fatigue specimens to improving the fatigue properties of bolt’s material. The tests of mechanical properties and fatigue behavior were carried for material that the bolt manufacture from it, a region where the failure occur and inserted of these properties to the program of engineering analysis (Ansys) to calculate the safety factor of fatigue. The results showed that the safety factor after hardening by laser is increased by 42.8%.

Ductile cast iron is also called spheroidal graphite cast iron or nodular cast iron. It contains graphite in the semblance of nodules. Automobile scrap (i.e., the engine block) made from gray cast iron was used in this study. In this paper, the recycling of gray cast iron to ductile iron, and its influence on the microstructure and mechanical characteristics be studied. Four kilograms of scrap were put in a crucible and then heated up to 1400°C in an oil-fired crucible furnace. For desulfurization, 4% burnt lime with 0.5% fluorspar was direct tapped into the melt at 1400°C. Then, the additions were 3.5% nickel, 0.75% Ferro molybdenum, and 0.5% Ferro manganese of the scrap weighing. Also, 3.75% nodularizing alloy and 1% inoculating alloy of scrap weight were to treat the molten at 1450°C. Samples analyses have been achieved to determine their composition, tensile strength, impact strength, Brinell hardness, and microstructural. The microstructures revealed that the scrap sample possesses flake graphite, and the produced sample includes nodule graphite. It is observed that the ultimate tensile stress, elongation, and hardness of the scrap sample, which are 247.75 MPa, 6%, and 400.3 HB, respectively, increased in the product sample to 416.23 MPa, 8%, and 451 HB, respectively.

A theoretical and experimental investigation pertaining to the buckling behavior of slender fiber reinforced polymer columns subjected to axial loading under varying temperatures (from room temperature to 50℃). Two groups of composite materials were used for manufacturing of test specimens, the first consist of perlon fiber as a reinforcement and acrylic resin as a bonding matrix, while the second consists of a combination of perlon and carbon fibers as reinforcement. The composite specimens were fabricated by vacuum molding technique and cut according to ASTM D-638 for conducting tensile test. The data from tensile test were used to calculate the effective slenderness ratio and defining the column as Euler buckling column. An experimental rig was designed, manufactured and calibrated to study the effect of thermal and buckling load subjected to columns. Numerical analyses pertaining the buckling behavior for both groups were conducted. The results show that the temperature has a considerable effect on properties of fiber reinforced polymer composites where the value of critical load and Young's Modules decrease with the increase of temperature for both groups. Perlon & Carbon reinforcement composites gave best mechanical properties, which make them the best candidate to improve the buckling resistance characteristics of composite materials.

This paper presents is the study and analysis of failure mechanism of non-articular prosthetic foot (SACH) in the region (Bolt Adapter). The tests of mechanical properties and fatigue behavior were carried for material of which the bolt manufacture from it is a region where the failure occurs out and inserted of these properties to the program of engineering analysis (Ansys) to calculate the safety factor of fatigue and stress equivalent (Von-Mises).The results that both, showed the maximum equivalent stress and the minimum safety factor of fatigue are located in bolt at interface region between the adapter and the foot at notch, however, in static case, the effect was on the ground reaction force at toe off phase more than heel strike phase.

Friction stir welding (FSW), a solid-state welding process, it’s involve a welding by friction between two metals or alloys, and also using for the joining of dissimilar materials due to the lower processing temperature over conventional fusion welding, it's include only one pass of welding. Friction Stir Processing (FSP) is a recent outgrowth of the Friction Stir Welding (FSW) process and relies on solid-state deformation to modify the structure of the workpiece, it's involve two pass or more of welding and applied either on the base metal(BM) or to join the two alloys/metals. In this paper the new method used, namely reverse rotation friction stir processing (RFSP), this research aims to study the effect of (RFSP) technique on the mechanical properties of welded alloys. (FSW) includes a single pass of the welding line but the second method (RFSP) involves two pass of welding (forth and back) but the 1st pass with a rotation speed in clockwise and the 2nd pass in counter-clockwise. The alloys used of dissimilar AA 2024 and AA6061 aluminum alloys of (3mm) thickness, the parameters used in this research include different rotational speed (1600, 1800, 2000 and 2200) RPM and one feed speed (25) mm/min. In the tensile test the results of reverse rotation friction stir processing (RFSP) was higher than friction stir welding (FSW) for all rotation speeds of welding except (1800 RPM). In the microhardness measurement the values of hardness for all samples at the nugget zone is higher than the basemetal of 6061-T6 and lower than the basemetal of 2024-T3. The efficiency of ultimate tensile strength reaches to about (72 %) for (RFSP) as compare with value of (FSW) and it’s about (44%) at rotation speed (1600 RPM).The only exception of welding was when the rotational speed of (1800 RPM), where the (FSW) is better than (RFSP), efficiency was approximately (77%) for the (FSW) compared with the results of (71%) (RFSP).

Abstract In this study a Nickel-Titanium-Cupper shape memory alloys was manufactured by powder metallurgy (PM) technique, powder mixture of 50% Ti , 47% Ni and 3% Cu was prepared by mixing for two hours and compacted in a press machine using various compacting pressure (600, 700 and 800) MPa , sample was then sintered for 5 hrs in an electrical tube vacuum furnace using sintering temperature of (850˚C, 900˚C and 950˚C) .phase analysis of samples was conducted by X-ray diffraction test, the effect of different sintering temperature and compacting pressure on the porosity, microhardness ,compression strength and the shape memory effect (SME) was studied, the result showed decrease in the porosity and increasing in the shape recovery ,compression strength and microhardness with increasing compacting pressure and at lower sintering temperature and hence the best results was at 800MPa compacting pressure and 850˚C sintering temperature.

Friction stir processing is a new method of changing the properties of a metal through intense, localized plastic deformation ,this process mixes the material without changing the phase (by melting or otherwise) and creates a micro structure with fine, equiaxedgrains, It is used to improve the micro structural properties of metals. In this paper , the enhancement of mechanical properties of friction stir welding specimens at variable rotation speeds (1100,1300 and 1500 rpm ) with constant feed speed(60 mm/min) for 6061-T6 aluminum alloy is studied by using the friction stir processing method at the same variable rotation speed and feed speed in order to transform a heterogeneous micro structure to a more homogeneous, refined micro structure. The best results of the weld gained at the parameter 60 mm/min weld speed and 1300 RPM rotation speed for the FSW and FSP where the efficiency reaches to 84.61% for FSW and 89.05% for FSP of the ultimate tensile strength of the parent metal .This research is developed a finite element simulation of friction stir processing (FSP) of 6061-T6 Aluminum alloy. Numerical simulations are developed for thermal conductivity, specific heat and density to know the relationship of these factors with peak temperature, The simulation model is tested with experimental results. The results of the simulation are in excellent comparison with the experimental results.

The effects of stress on dental restoration and upon teeth themselves have been a topic of interest to dental researchers for the past twenty years. A model of a maxillary central incisor (front tooth) restored with titanium alloy post and another post nickel alloy in combination with different cements, are established. The stress in dentin, posts, cores and crowns have been evaluated and compared with two different post materials and two different cements. The research is performed theoretically , numerically and experimentally, A composite beam formula is derived for analysis and the stress at sections through the tooth. The numerical analysis is achieved by use of ANSYS/ver.11 software. The material of tooth is assumed to be isotropic, homogeneous and elastic. A load of 100 N is applied at an angle of 45۫ to the longitudinal axis at the palatal surface of the crown. The mechanical properties and chemical composition of nickel alloy and Zinc polycarboxylate are measured experimentally. In this study , There are three model type (I,II and III) , model I including the standards restoring tooth (Titanium post tooth ), model II including new post (Ni-Cr) alloys and third model by using the high strength cement(Zinc polycarboxylate) .

The Standard prosthetic pylon is manufactured from aluminum -titanium alloys as a result of lightweight. In this study, a three prosthetic pylons are designed and manufactured from different layers of composite materials (6 layers,9 layers and 12 layers ). The mechanical properties such as σy and σult and σe were measured for all types of the pylon, Also, the design pylon fatigue tester and impact pylon test then all pylons were tested by this device. All types of new prosthetic pylons are light and cheap compared with the standard pylon Therefore, to choose the best pylon, the weighted method is preferred, this method depend on practical experience. This method the optimum choice pylon (kp) , it explains that the Pylon II is good.