Farag I. Haider

Influence of Oxalate Concentration and Temperature on the Microstructure Morphology of Nano Anodized Copper Coating

Nanostructures anodized copper coating was successfully synthesized through electrochemical anodization method. Effects of oxalate concentration and temperature on the morphology and corrosion resistance of the anodized coating were investigated through the observation of the critical polarization current variations. The anodizing parameters were selected in the ranges of anodizing temperature 0-24 °C, oxalate concentration 0.1-0.5 M and applied voltage 7.5-9 V. Phase analysis of the anodized coating was carried out using XRD (X-ray diffraction). Resulted peaks of the X-ray diffraction referred to the formation of a monoclinic crystalline phase of nanostructure cupric oxide CuO. The results of critical polarizing current were analyzed to evaluate the charge transfer through the coating. The lowest critical polarizing current was obtained when the porosity of the coating was in its lowest values. The increasing of oxalate concentration increases solution conductivity leading to form coating of larger grain size with fewer pores. The decreasing of temperature decrease coating porosity. The highest resistance to charge transfer through the anodized coated surface was achieved in the highest oxalate concentration and lowest anodizing temperature.

Modelling and Optimization of Copper Electroplating Adhesion Strength

In this paper, Response surface methodology (RSM) was utilized to design the experiments at the settings of CuSO4 and H2SO4 concentrations and current densities. It also used for modelling and optimize the parameters on the adhesion strength of austenitic stainless steel substrate. The adhesion strength was investigated by the Teer ST-30 tester, and the structure of the samples investigated by using scanning electron microscopy (SEM). The modelling approach adopted in the present investigation can be used to predict the adhesion strength of the copper coatings on stainless steel substrate of electroplating parameters in ranges of CuSO4 100 to 200 g / L, H2SO4 100 to 200 g / L and current density 40 to 80 mA / cm2. The results showed that, operating condition should be controlled at 200 g/L CuSO4, 100 g/L H2SO4 and 80 mA/cm2, to obtain the maximum adhesion strength 10N.

Evaluation of the effects of copper electroplating parameters on the adhesion using response surface methodology

In this paper, response surface methodology (RSM) was utilized for the experiment design of CuSO4 and H2SO4 concentrations and current densities. RSM was also used to evaluate the significance of each parameter and its interaction on the adhesion strength of austenitic stainless steel substrate. Adhesion strength was investigated by a Teer ST-30 tester, and the structure of the samples investigated by using scanning electron microscopy (SEM). Results showed that increasing the concentration of CuSO4 and decreasing theat of H2SO4 strengthens adhesion. Conversely, the current density only has a slight effect.

Heat Treatment Recycling of Dual Phase Region and its Effect on Hardness, Microstructure and Corrosion Rate of Medium Carbon Steel

In this work, the investigations were carried out to study the effect of heat treatment at dual phase of austenite and ferrite on mechanical properties , microstructure and corrosion rate of low alloyed medium carbon steel. The specimens were divided into five groups, first group, specimens were heated to the duel phase region at temperature of 740°C soaked for 30 minutes and quenched in water. The second group, The specimens were heated to 740°C soaked for 30 minutes and quenched in water, then tempered to 480°C soaked for 20 minutes. The third group the specimens were heated to austenizing temperature of 840°C soaked for 30 minutes and quenched in water, then the specimens reheated to the dual phase region at 740°C, soaked for 30 minutes and quenched in water, then the specimens were tempered at temperature 480°C for 30 minutes. The forth group, the specimens were heated to austenizing temperature of 840°C soaked for 30 minutes and quenched in water, this process were repeated again before the specimens were thereafter heated to the dual phase region at temperature of 740°C, soaked for 20 minutes and quenched in water, then the specimens were tempered at temperature 480°C for 20 minutes. The fifth group, the specimens were heated to austenizing temperature of 840°C soaked for 20 minutes and quenched in water, this process were repeated two times again before the specimens were thereafter heated to the dual phase region at temperature of 740°C, soaked for 20 minutes and quenched in water, then the specimens finally tempered at temperature 480°C for 20 minutes. The results proved the hardness increase after heat treatment at first and second group, at third group the highest hardness value was due to formation of martensite and ferrite, but at fourth and fifth groups hardness decreases due to appearance of carbides particles, also corrosion rate usually increases with two phase at microstructure than stable one phase, third group have less corrosion rate than fourth and fifth due to carbides particles formation which lead to more corrosion rate due to three phases presents.

The effect of heat treatment of gray and nodular cast iron with ferrite matrix on mechanical properties and corrosion rate compared with medium carbon steel

In this work, the influence of heat treatment process and quenching in different quenchant media of medium carbon steel, gray and nodular cast iron with ferrite matrix on the hardness, ductility and corrosion rate of has been investigated. During this type of operations, the specimens were Austenizing at 900°C for one hour. Therefore, the specimens were quenched in different kind of oil as quenched medium (oil 20-50, oil 40, oil 90, and water as reference). The hardness , impact energy to measure the ductility, corrosion rate and microstructures were studied. From result of steel 0.47% carbon was clear increasing in hardness and decreasing in ductility with close varying values in oil quenchant kind comparing with as received specimen and water quenched one, corrosion rate decreased with heat treatment and quenching process due to formation of single face instead of double phase before heat treatment process which created galvanic cell. For gray and nodular cast iron it is noticeable that no changing in microstructure within heating for one hour at 900°C because the matrix in both cast iron types is ferrite, therefore no changing in mechanical properties under heat treatment process with time of one hour which is not sufficient to decomposition of graphite, but with comparison the hardness of gray cast iron is more than nodular one due to distribution of graphite flacks which increase the hardness and decrease the ductility as well as increasesing the corrosion rate compared with nodular cast iron. Microstructure of both types of cast iron have been studied after subjected the specimens to heat treatment at 1000°C and for 10 hours, the microstructures shown clear diffusion of some carbon in ferrite matrix around the graphite phase and under quenched some of martensite formed.

Evaluation of the Performance of Cylinder Liner under Dry Reciprocating Wear Conditions

The aim of this work is to study the wear behavior of the cylinder liner of internalcombustion engines, using reciprocating wear testing machine and study the effect of operating conditions (Rotating speed, length of stroke and normal load) on the wear behavior in dry sliding. A statistical analysis method was applied to study the interaction effect of these parameters, and effect of each parameter. Results obtained showed that the wear characteristics is effected mainly by the normal load (P), and stroke length (L), and the rotating speed (R) has no significant effect on the liner wear. The study also showed an interaction effect of normal load (P), and stroke length (L) together on the wear of the liner.