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Hydraulic systems that operate for long periods of time eventually develop high oil temperatures that have damaging effects on machine performance. If the temperature rise is excessive, the oil viscosity drops, lubricating properties are lost and in the worst cases the whole system can be seriously damaged. A mathematical model for predicting temperature distribution in hydraulic systems has been developed with taking into account the thermodynamic processes and the effects of heat transfer by conduction, radiation and convection. In order to test this model experimentally, a complete hydraulic mixer system has been designed, instrumented and commissioned. A software package for hydraulic systems has been developed to make accurate estimation for unsteady state temperature analysis in hydraulic systems at any time during its operation. The simulation results of this package have shown that this model is more accurate than that reported elsewhere.

This paper gives a review of the finite element techniques (FE) applied in the area of material processing. The latest trends in metal forming, non‐metal forming and powder metallurgy are briefly discussed. The range of applications of finite elements on the subjects is extremely wide and cannot be presented in a single paper; therefore the aim of the paper is to give FE users only an encyclopaedic view of the different possibilities that exist today in the various fields mentioned above. An appendix included at the end of the paper presents a bibliography on finite element applications in material processing for the last five years, and more than 1100 references are listed.

Inconel 617 alloy is widely used in industry due to its superior high temperature properties. After long periods of operation, the alloy microstructure changes. One of the methods to regain the alloy microstructure is heat treatment at elevated temperatures. In the present study, electrochemical and mechanical responses of Inconel 617 alloy over 30,000 hours of operation as a transition‐piece in agas turbine engine are examined. The heat treatment process at two different temperature levels is applied when refurbishing the alloy microstructure. The electrochemical tests are conducted to investigate the corrosion response of the alloy before and after the heat treatment process. Fatigue and tensile tests are carried out for the workpieces subjected to the electrochemical tests. SEM is introduced to examine the fractured surfaces.

The features of coated wire product are measured by the flow and heat transport occurring in the interior of dies. Therefore, an understanding of characteristics of polymers momentum, heat mass transfer and wall shear stress is of great interest. Enhancement of heat transfer rate is fundamental need of wire coating process. Therefore, this study aims to investigate the effect of suspended nanoparticles in heat and mass transport phenomena of third-grade liquid in post-treatment of wire coating process. Buongiorno model for nanofluid is adopted. Two cases of temperature dependent viscosity are considered.

The governing equations are modelled with the help of steady-state conservation equations of mass, momentum, energy and nanoparticle concentration. Some appropriate dimensionless variables are introduced. Numerical solutions for the nonlinear problem are developed through Runge–Kutta–Fehlberg technique. The outcome of sundry variables for dimensionless flow, thermal and nanoparticle volume fraction fields are scrutinised through graphical illustrations.

The study’s numerical results disclose that the force on the total wire surface and shear stress at the surface in case of Reynolds Model dominate Vogel’s Model case. Impact of nanoparticles is constructive for force on the total wire surface and shear stress at the surface. The velocity of the coating material can be enhanced by the non-Newtonian property.

This study may provide useful information to improve the wire coating technology.

Effect of nanoparticles in wire coating analysis by using Brownian motion and thermophoresis slip mechanisms is investigated for the first time. Two different models for variable viscosity are used.

This paper presents a study of the development of surface roughness model when turning the mild steel hardened up to 484 HV with mixed alumina ceramic (KY1615) and coated alumina ceramic cutting tools (KY4400). The model was developed in terms of main cutting parameters such as cutting speed, feed rate and depth of cut, using response surface methodology. The established equation indicated that the feed rate affected the surface roughness the most, but other parametres remined stable for arithmetic average height parametre (Ra). However, it decreased with increasing the cutting speed, and with the starting and finishing point of cut for ten point height parametre (Rz). The cutting speed and the depth of cut had a slight effect on surface roughness values of Ra, Rz when using KY4400 cutting tools. Furthermore, the average surface roughness value of Ra was about 0.926 um, 1.089 um for KY1615, KY4400 cutting tools, respectively. The predicted surface roughness was found to be very close to experimentally observed ones at 95% confidence level. Moreover, analysis of variance indicated that squares terms were significant but interaction terms were insignificant for both cutting tools.

To examine the tensile properties of high velocity oxy‐fuel (HVOF) sprayed Inconel 625 coating of steel substrate before and after the aqueous corrosion.

Workpieces were cut from steel sheets. After chemical and ultrasonic cleaning, workpiece surfaces were sand blasted and HVOF sprayed Inconel 625 coated. The coated and un‐coated surfaces were subjected to the aqueous corrosion tests for one and three weeks. After the completion of the corrosion tests, tensile properties of the workpieces were examined.

The workpieces subjected to a three weeks static corrosion environment fail at a lower load than the untreated workpiece due to high stiffness. The defect sites in the coating and at the interface act as stress risers and contribute substantially crack initiation and propagation in the coating. Under increasing tensile load in the plastic region, the substrate material can no longer support the coating. This results in extended cracking and gradually spalling of the coat. When the local critical stress for crack propagation is reached, elongated cracks occur, which in turn initiates splitting separation between the adjacent zones in the coating. The shear deformation of the adjusted zones results in the total failures of the coating.

The tests can be extended to include the duplex treated workpieces such as the laser treatment of surface after HVOF sprayed coating. This enhances the bonding of the coating through thermal integration of the coating and the base substrate material.

The results can be used to assess the HVOF sprayed coatings.

This paper provides information on mechanical behavior of HVOF sprayed coating when subjected to the tensile force and offers practical help for the researchers and scientists working in the coating area.

This paper seeks to examine the fatigue properties of HVOF sprayed Inconel‐625 coating of steel substrate before and after the aqueous corrosion.

Workpieces were cut from steel sheets. After chemical and ultrasonic cleaning, workpiece surfaces were sand‐blasted and HVOF sprayed Inconel‐625 coated. The coated and un‐coated surfaces were subjected to the aqueous corrosion tests for one and three weeks. After the completion of the corrosion tests, fatigue properties of the workpieces were examined.

Stainless steel coated workpieces demonstrated excellent fatigue life resistance versus coated carbon steel workpieces. Stainless steel workpieces apparently have a high‐cycle fatigue represented by in excess of 1.50 million cycles without cracking, thereby assuring a high‐fatigue life. The carbon steel specimens have low‐cycle fatigue and consequently a short fatigue life. In addition, high velocity impacting of splats on to the workpiece enhances the hardness of the surface. This, in turn, improves fatigue properties at the interface, particularly for stainless steel workpieces.

The tests can be extended to include the duplex treated workpieces such as the laser treatment of surface after HVOF sprayed coating. This enhances the bonding of the coating through thermal integration of the coating and the base substrate material.

The results can be used to assess the HVOF sprayed coatings.

This paper provides information on the fatigue behavior of HVOF sprayed coatings when subjected to the cyclic load and offers practical help for the researchers and scientists working in the coatings area.

The paper seeks to understand the adoption rates of total quality management (TQM) by New Zealand firms, and the role that organisational size plays in determining adoption rates.

A survey of 997 random New Zealand firms of all sizes yielded 228 responses. Factors tested to predict TQM adoption were organisational size, workplace autonomy, performance standards, use of teams and group problem solving. In addition, organisational size was tested as a potential moderating variable on the other factors.

Overall, 33 per cent of firms in New Zealand used TQM, with an addition 5 per cent no longer using TQM, indicating strong adoption rates by international standards. All the direct effects and moderating effects were supported. Consequently, firms with higher level of workplace autonomy, use of performance standards, use of teams, and use of group problem solving were more likely to have adopted TQM, and this was more likely for larger firms than smaller firms. As a result, strong support was found for the interacting effect of organisational size.

The implications are that TQM adoption rates are much higher in New Zealand than suggested in the international literature. A highlight of the present study is the focus on firms of all sizes, rather than being limited to only larger sized firms.

This paper provides much needed information on the state of TQM in New Zealand and provides a unique approach by testing the moderating effects of organisational size on predictor factors on New Zealand firms.

This paper aims to depict the erosion performance of two HVOF-coated micron layers (Colmonoy-88 and Stellite-6) on pump impeller steel (SS-410) by using Taguchi's method. Taguchi's array (L16) was used to optimize the erosion wear (in terms of weight loss) by using four influencing parameters such as rotational speed, solid concentration, average particle size and time which were varied at four different levels.

The experiments were carried out by using a Ducom slurry tester with rotational speed in the range of 750-1,500 rpm, solid concentration of 35-65 per cent by weight, time period of 75-210 min and average particle sizes in the range of < 53 to 250 µm. Bottom Ash with a nominal size range of < 53 to 250 µm was used as erodent. The process parameters were optimized by using Taguchi's method. The ANOVA method was used to validate the results given by Taguchi's method.

The results revealed that the presence of both carbides and borides and the additional presence of Cr in Colmonoy-88 coating enhancing the slurry erosion resistance of Colmonoy-88 coating. Moreover, the chromium and tungsten carbide particles help in increasing the bond strength between the coating and the substrate material. Further, it was also found that the time was the most dominant factor as compared to other factors.

The very less work has been reported on optimization of erosion wear response of Colmonoy-88 and Stellite-6 coatings by using different design of experiment techniques. Further, the erosion wear mechanism of both coatings has been studied by using image j analysis software.

The Finite Element Method and Response Surface Method are used to find the effect of milling parameters (Cutting speed, Feedrate and Axial depth) on plastic strain when milling Hastelloy C‐22HS. This simulation gain more understanding of the strain distribution in metal cutting. Response surface method (RSM) has been used to minimize the number of simulation. The contour plot from the RSM shows the relationship between variables (cutting speed, feedrate and axial depth) and response (plastic strain ‐ rate).The friction interaction along the tool‐chip interface is modeled with Coulomb friction law.