Titanium is a strong metal known for its high strength-to-weight ratio. It is quite
ductile, lustrous and metallic white in color with low electrical and thermal conductivity. In view of its high melting point, 1650 oC, it is used as a refractory metal. Due to its high corrosion resistance, fatigue resistance, high crack resistance, and ability to withstand moderately high temperatures without creeping titanium alloys are used in aircraft, armor plating, naval ships, spacecraft and missiles.

Nevertheless, its wear resistance is poor and surface damage usually occurs in areas under contact loadings. As is known, wear is a phenomenon that is primarily determined by the surface properties of the material rather than by bulk properties. Therefore, surface modification techniques offer a solution to this problem. Thus came into vogue laser cladding as a suitable technique to increase the wear and corrosion resistance of titanium.

Against this backdrop, the authors, Hashem F El-Labban and Essam R I Mahmoud of the first paper, “Characterization of Commercially Pure Titanium Laser Cladded with TiC Particles”, have studied the applicability of YAG fiber laser with high power (1700-2800 W) in cladding Commercially Pure Titanium (CPTi) with TiC powder of 3-10 mm particle size at fixed traveling speed of 4 mm/s with argon as a shielding gas to improve the wear resistance of pure titanium and presented their findings. The powder was replaced on the top surface of the specimens with thickness of 1.0 and 0.5 mm. One and two laser passes were applied. The treated specimens were investigated using optical and scanning electron microscopes. Hardness measurements were also carried out through the thickness of the laser treated specimens. The authors concluded: one, surface cladding layers of Ti-TiC composite can be successfully produced on CP-Ti using YAG fiber laser; two, increased processing power resulted in increased depths of cladding layer; three, hardened zones of depths ranging from 0.7 to 1.2 mm were obtained by increasing processing power from 1700 to 2800 W; and four, the surface hardness of cladded layer was improved by 13 times as that of the substance at 1700 W.

In the next paper, “Performance Modeling and Analysis of the Bottling System of a Beverage Industry” the authors, Parveen Kumar and P C Tewari, have addressed the issue of maintaining the industrial systems that are increasingly becoming complex, failure-free and operate continuously. In this regard, they have analyzed the performance of bottling system—with subsystems such as uncaser, bottle washer, filling machine, pasteurizer, cooling tunnel, crowner and coding machine—of the beverage industry for developing a model that ensures continuous operations. The system behavior is modeled using Markovian approach. Based on their analysis, they found that the bottle washer as the most critical subsystem should be given priority for maintenance followed by filling machine as the effect of its failure and repair rate on the system was found to be much higher than the other subsystems.

In the next paper, “Development of MR Damper Modeling and Its Experimental Validation” the authors, S K Mangal, Ashwani Kumar and K D Chattopadhyay, have developed two mathematical models of the magnetic circuit of the magneto-rheological damper and presented the results of the experiments meant for validating the models at various input current levels. To accomplish this objective, the authors have fabricated a prototype of the MR Damper and tested it in the vibration control laboratory. The comparative analysis of the models indicates that the maximum percentage error in the damping force remained almost same over a wide range of input current supplied to the electromagnetic coil of the MR damper and thus validates the mathematical and FEM models presented by them. The damping force is, however, found to be increasing with the increase in the magnetic field strength.

In the next paper, “Computation of Overall Equipment Effectiveness in Connecting Rod Manufacturing Operations”, the authors, S S Sonigra and M N Qureshi, have presented a method to compute Overall Equipment Effectiveness (OEE) in connecting rod manufacturing operations. According to them, the OEE sheet helps the management to assess the current state and plan the future state of operations to improve the overall performance. Based on their study, the authors have identified different types of manufacturing processes where the OEE sheet can be applied meaningfully for better performance.

In the next paper, “Sliding Wear Behavior of HVOF Sprayed Abradable Coating”, the authors, Bharat Atray, Ajay Malik and Atul Raj, have presented the results of the sliding wear behavior of Al-Si/40 polyester thermal spray coatings deposited on aluminum alloy substrates using a HVOF spraying process at different operating parameters. The specimen preparation and the experimentation were carried out as per ASTM G99 standards. Wear tests were carried out using a pin-on-disc type wear tester within a load range of 20-70 N, sliding speed range of 0.2-2 m/s and sliding distance of 1000-5000 m. The optimum combination of parameters and their levels for obtaining minimum wear rate were also found using DOE technique. The results indicate that the wear rates of coating were minimum at low load in high sliding speed and the optimum combination of parameters and their levels for obtaining minimum wear rate were A1B3C1.

In the last paper, “The Effect of Temperature and Total Solid on Biomethanation of Sugarcane Bagasse”, the authors, Manjula Das Ghatak and P Mahanta, have investigated the effect of temperature of 35 oC, 40 oC, 45 oC, 50 oC, 55 oC and total solid concentration of 6%, 9% and 12% on biogas generation and found that biogas production was highest with 9% total solid concentration at 55 oC temperature.

GRK Murty
Consulting Editor