An investigation to the Effect of Copper Addition on the Characteristics of Ni-Ti Shape Memory Alloy

The effect of Cu addition on the physical and mechanical properties of Nickel-Titanium (weight percentage ) shape memory alloy were investigated , density , porosity , compression strength ,Shape Effect (strain recovery), ,micro-hardness , Conducted to estimate the Cu effect ,a Different amount of Cu (2%,5%,10% ) weight percent were added with different compacting Pressure (450MPa and 600MPa). Significant effect on master alloys properties especially the alloys that have 5%Cu and 10%Cu has been observed

The Optimization Conditions of Friction Stir Welding (FSW) for Different Rotational and Weld speeds

The effect of welding parameters on mechanical properties of aluminum alloy 3003 H14 Friction stir-welded (FSW) joints were investigated in the present study. Different welded specimens were produced by employing variable rotating speeds (1000, 1250, 1500, 2000 r.p.m.), and welding speeds (20, 40, 60, 80 mm/min). Microhardness measurements and tensile strength of the produced joints were tested. The experimental results indicated that the process parameters have a significant effect on mechanical properties of joints. The optimum results of the weld gained at the parameter 80mm/min weld speed and 1500 rpm rotation speed where the efficiency reaches to 89% of the ultimate tensile strength of the parent meta

An Experimental Investigation on Fatigue Properties of AA3003-H14 Aluminum alloy Friction Stir Welds

AA3003-H14 aluminum alloy plates were welded by friction stir welding and TIG welding. Fatigue properties of the welded joints were evaluated based on the superior tensile properties for FSW at 1500 rpm rotational speed and 80 mm/min welding speed. However, there is not much information available on effect of welding parameters with evolution of fatigue life of friction stir welds. The present study experimentally analyzed fatigue properties for base, FSW, and TIG welds of AA 3003-H14 aluminum alloy. Fatigue properties of FSW joints were slightly lower than the base metal and higher than TIG welding

Vibration Measurement and Analysis of knee-Ankle-Foot Orthosis (KAFO) Metal-Metal type

This paper deals with calculate stresses in Knee-Ankle-Foot-Orthosis as a result of the effect vibration during gait cycle for patient wearing KAFO .Experimental part included measurement interface pressure between KAFO and leg due to action muscles and body weigh on Orthosis. also measurement acceleration result from motion of defected leg by accelerometer .Results of Experimental part used input in theoretical part so as to calculate stresses result from applying pressure and acceleration on KAFO by engineering analysis program ANSYS 14.Resultes show stresses values in upper KAFO greater than lower KAFO that is back to muscles more effective in thigh part lead to recoding pressure higher than pressure in shank part

Study the Mechanical Properties and Numerical Evaluation of Friction Stir Processing (FSP) for 6061-T6 Aluminum Alloys

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

Investigate the Microstructure and the Mechanical Properties of Ni-Ti-Cu Shape Memory Alloys

        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

Effect of Nb Addition on Hardness and Wear Resist of Cu-Al-Ni Shape Memory Alloy Fabricated By Powder Metallurgy

Cu-Al-Ni shape memory alloy specimens has been fabricated using powder metallurgy technique with tube furnace and vacuum sintering environment , three range of Nb powder weight percentage (0.3,0.6,0.9)% has been added. Micro hardness and sliding wear resist has been tested followed by X-ray diffraction, scanning electron microscope (SEM) and energy dispersive X-ray spectroscope (EDX) for micro structure observation. The experimental test for the samples has showed that the increase of Nb powder weight percentage in the master alloy has a significant effect on increasing the hardness and decreasing the wear resist therefore it will enhance the mechanical properties for this alloy

EFFECT OF TOOL SHOULDER DIAMETER ON THE MECHANICAL PROPERTIES OF 1200 ALUMINUM FRICTION STIR SPOT WELDING

A friction stir spot welding (FSSW) process is an emerging solid state joining process in which the material that is being welded does not melt. In this investigation an attempt has been made to understand the effect of tool shoulder diameter on the mechanical properties of the joint. For this purpose four welding tools diameter (10,13, 16 and 19) mm at constant preheating time and plunging time were used to carry out welding process. Effect of tool diameter on mechanical properties of welded joints was investigated using shear stress test and Microhardness of joint which welded was studied. Based on the stir welding experiments conducted in this study the results show that aluminum alloy (1200) can be welded using (FSSW) process with maximum welding efficiency (80%) shear strength using tool diameter(19mm) with rotation speed (900rpm)

Optimization of Friction Stir Spot Welding Parameters of Al6061T6 by Hybrid Approached

The most important way for joining the non-welding aluminum alloy is Friction stir spot welding. Three parameters effect on efficiency of welding: tool shape, rotational speed, and plunged time, are chosen to study for welding 6061T6 aluminum alloy. Each of the above parameters has three variables as: pin shapes (square, cylinder, and hexagonal), plunged time (50, 70,100) sec  and rotational speeds (710, 1120, 1800) rpm hybrid approach which is consist of the experiment run, neural network and social spider optimization is used to optimize the welding conditions by finding the maximum ultimate force. The best condition of the weldments is (square, 710rpm, 100sec) with maximum shear force 4740N. The best results obtained from hybrid optimization with experimental results; with discrepancy of 2%

A review on EMG/EEG based control scheme of upper limb rehabilitation robots for stroke patients

Stroke is a common worldwide health problem and a crucial contributor to gained disability. The abilities of people, who are subjected to stroke, to live independently are significantly affected since affected upper limbs' functions are essential for our daily life. This review article focuses on emerging trends in BCI-controlled rehabilitation techniques based on EMG, EEG, or EGM + EEG signals in the last few years. Working on developing rehabilitation robotics, is considered a wealthy scientific area for researchers in the last period. There is a significant advantage that the human acquires from the interaction between the machine and his body, rehabilitation for a patient's limb is very important to get the body limb recovery, and this is what is provided mostly by applying robotic devices