Iraqi journal of mechanical and material engineering

In this research studied the effect of corrosion in presence of vibration on aluminum alloy type (DIN1100) operating in sea water (3.5% NaCl) and compared these results with the same alloy after it was welded by TIG technique at the same vibrated corrosive medium, addition to study the corrosion in static medium for welded and non- welded alloy, then comparison between the four cases depending on corrosion rates and microstructures it was noted that ;the greatest percentage of corrosion rate was 43% of welded alloy at vibration-corrosion and least percentage of corrosion rate was 8% of non-welded alloy at static corrosion.

Although, the PMMA have good advantages made it appropriate to denture base applications. But its low impact and fracture strength represent the main drawbacks of it.so many studies had been done in order to overcome these problems. In this study Pistachio Shell powder was added in different weight fractions of about (3, 6, 9 and 12 wt. %) and different average particle sizes of about (53μm, 106μm, 150μm and212μm) to (heat-cure) PMMA that is popularly utilize in denture base applications and study the Fourier transform infrared spectroscopy (FTIR) and Differential Scanning Calorimeter (DSC) behavior of this bio composite. The results were as the following: the FTIR results demonstrated that there are no new peaks appeared after the reinforcing by Pistachio Shell
powder. Also there was no shifting in any of these peaks. While the DSC test showed that the glass transition temperature (Tg) increased as the particle size of Pistachio Shell powder increased. The highest value of Tg (126.9℃) was obtained for composite specimen reinforced with 12% of Pistachio Shell powder with average particle size of about (212μm).

This research is devoted to study the influence of different weight percent concerning to the additions of Ti and Cu on corrosion- fatigue and electrical properties of AA6061. The composite materials consist of different weight percentage of Ti (0.2, 0.4, and 0.6) and constant weight percentage of Cu (0.2) are fabricated by liquid metallurgy route technique.Attempts have been made to explore the impact of corrosive media on the fatigue behavior of AA6061 submerged for 80days in shat al Arab water. Constant and variable corrosion fatigue tests are performed under rotating bending loads and stress control at the stress ratio R= -1 and room temperature (RT). The results show the fatigue strength reduction due to corrosion without nano materials increases with the increasing of the testing cycles, but when adding nano material the fatigue strength reduction will be reduced with increasing the testing life. Furthermore the results of electrical tests show that increasing electrical conductivity and decrease of resistivity.

CoCrMo alloys are used as biomaterial due to their good corrosion and wear resistance, with reasonable biocompatibility. The present study aims to investigate the effect of (1, 3 and 5) wt% α-Al2O3 nanoparticle additions on some properties of pre-alloyed CoCrMo when fabricated by powder metallurgy route. The density, porosity, microhardness and microstructure of the fabricated samples were examined. The results revealed that the addition of α-Al2O3 nanoparticle has a distinguished effect on the density of sintered CoCrMo alloy samples, where continues increase in the porosity was happened and reached to its maximum value at the higher addition amount. While the density showed an inverse trend to that of the porosity with the increasing of the nanoparticle addition. The microhardness was decreased as the amount of the nanoparticle addition to CoCrMo alloy was increased. The microstructure observation by SEM and SEM-Mapping is revealed the partial isolation of CoCrMo particles by the nanoparticle additions and it was associated with the formation of passive Cr2O3 oxide. In turn the XRD analysis depicted the co-existence of γ-Co and ε-Co phases besides, the Cr2O3 oxide. Although the increased porosity with the nanoparticle addition but, this will perhaps, increase the tissue ingrowth when the fabricated nanocomposites were utilized as biomaterial.

Cathode ray tube like as electronic waste is a green crisis due to its toxicity. Remove of the lead from CRT funnel glass can prevent it from release into the environmental and allow it reuse. There are several ways to separation lead from its CRT funnel glass and then recovered from it. In this research, CRT funnel glass was treated by high thermal reduction method with using different additives. These additives that used in this method are sodium carbonate (Na2CO3 ) with (20, 25&30) wt% used as a melting agent, sodium sulfide ( Na2S) with (6, 8&10)wt% used as a catalytic agent and carbon powder (C) with (2.4, 3.6 &4.8) wt% used as a reducing agent, at fixed temperature (1100°C) and holding time (120 min). Taguchi technique for design of experiment (DOE) was applied to find the optimum process conditions of different additives for metallic lead recovery by high thermal reduction method. Experimental results presented that the maximum lead recovery was 97.36% when the optimum conditions were sodium carbonate (30%), sodium sulfide (10%), and carbon powder (3.6%) at 1100°C and 120 min.

This research study the properties of Non-Newtonian fluids. Eight samples of Non-Newtonian fluids were prepared, with constant concentration of Carboxy methyl cellulose (CMC) which was (2 gm/500cc), and different concentrations of weighting material (Bentonite). The concentrations of Bentonite were (8, 10, 12, 20, 26, 32, 36, 42) grams with 500 ml water. It was concluded that the increase in the concentration of Bentonite will increase the shear stress with the increase of shear rate. It was also concluded that the increase in the concentration of Bentonite will increase the plastic viscosity, yield point, and density of these Non-Newtonian fluids.

In this paper, the drawability of two-layer (steel-brass) sheets to produce square cup, is investigated through numerical simulations, and experimental tests. Each material has its own benefits and drawbacks in terms of its physical, chemical and mechanical properties, so that the point of this investigation is taking the benefits of different materials, like (low density, high strength and resistibility of corrosion), at the same time and in a one part. ANSYS18 software is used to simulate the deep drawing process of laminated sheet. The deep drawing processes for square cup were carried out under various blank holder loads with different lubrication conditions (dry and lubricant) and with variable layer arrangement. The materials were low carbon steel st1008 and brass CuZn30 sheets with thickness of 0.5mm0and 0.58mm respectively. The thickness of laminated sheet blank was 1.1 mm and its diameter was 83 mm. The drawn cups with less imperfections and satisfactory thickness distribution were formed in this study. It is concluded the greatest thinning appear in the corner of the cup near the punch radius due to extreme stretching take place in this area. Experimental forming load, blank holder load, and thickness distribution are compared with simulation results. Good agreement between experimental and numerical is evident.