Print ISSN: 1681-6900

Online ISSN: 2412-0758

Keywords : Zirconia

Effect of Thermally Sprayed Ceramic Coating on Properties of Low Alloy Steel

Fadhil A. Chyad; Abdalkalaq F. Hamood; Lamees S. Faiq

Engineering and Technology Journal, 2014, Volume 32, Issue 10, Pages 2568-2575

Thermal spraying technique was employed for coating low alloy steel specimens that have been used in a derrick oil well frames.
Two types of ceramic materials were used as a coating material and two groups of steel samples were prepared for coating process.
The first group was coated by zirconia while the second group was coated by alumina. Ni-Al composite powder was used forbonding the coating material on the substrate surface of the steel specimens.
The hardness, adhesion strength of the coating layers as well as wear rateswere studied for the two steel group samples and compared with as received steel.
The results showed an increase in the mechanical properties with a decrease in wear rate values for coated samples as compared to those of uncoated samples.

Fracture Statistics of Porcelain Ceramic: The Influence of Zirconia Additive and Sintering Temperature

Fadhil A.Chyad

Engineering and Technology Journal, 2013, Volume 31, Issue 6, Pages 1081-1091

The knowledge of statistic characteristics in mechanical properties is important for designer in order to asses the reliability of the structure. Scatter characteristics of fracture strength (splitting strength) of porcelain toughened by zirconia and the effect of sintering temperature were investigated in this study. Many specimens were tested by Brazillian method to obtain the scatter data of fracture strength. The probability distribution of fracture strength is evaluated by using Weibull ddistribution function.
Fracture strength is increased with zirconia content having the highest value (43MPa) at 10 wt.% and then decreased .The same behavior was for Weibull modulus, having the highest value (39) for 10 wt.% Zirconia .
Fracture strength and Weibull modulus also affected by sintering temperature, they increased with the increasing of sintering temperature.

The Effect of Zr loading on the Performance of Honeycomb Monolithic catalyst for the Removal of NO , CO and Hydrocarbon from Exhaust Gas

Hussain Khalaf; Shahrazed R.Rauof; Abdul Halim Abdul K.Mohammed

Engineering and Technology Journal, 2009, Volume 27, Issue 10, Pages 1915-1936

Catalytic monolith reactors have numerous applications in industrial
processes and as technical devices, so the focus is set specially on automotive catalytic converters. In present work the experimental and theoretical investigation has been carried out to study the performance of monolith reactor on the oxidation and reduction of exhaust gas (NO, CO, HC, O2 and H2O) which emitted from gasoline generator. Commercial ceramic monolith catalyst and catalyst loaded on the commercial with
Zr were used in the present work. A laboratory unit was constructed for this purpose where a versatile stainless steel reactor of 0.02 m inside diameter and 0.2 m height was used. The catalytic performance of the catalysts was studied in the following operating conditions: gas hourly space velocity in the range 17.69 – 44.23s-1, reaction temperature in the range 373 – 673 K, bed length in the range 0.075 – 0.15 m and
at atmospheric pressure and constant air / fuel ratio (14.6). The results show that the conversion of NO, CO, HC, O2 and H2O are slightly changed with the bed length, . The conversion of exhaust gas reactant enhances in presence of water (wet condition) rather than in the absence of water (dry condition) and increases with the increasing reaction temperature and decreases with increasing gas space
velocity. Commercial catalyst loaded with 0.4% Zr gives the higher performance for all components reaction