Malaysian Journal on Composites Science and Manufacturing

Numerical Investigation of Injection Pressure Effect on the Performance and Emission of a Diesel Engine Fueled with Butanol-Diesel Blends

Md. Radwanul Kabir — 2025-03-20

Globally, fossil-based resources are becoming increasingly scarce as the demand for energy from power-producing systems rises. Diesel engines are a popular and efficient source of electricity, but different national and international organizations have imposed limits on diesel emissions. Reducing emissions and boosting performance are typical operations in diesel engines. ANSYS FORTE code was used to generate a thorough numerical configuration. Analyses were conducted on a single-cylinder, four-stroke, direct-injection diesel Cummins N-14 test engine setup running on a 40 percent butanol-diesel blend with injection pressure ranging from 400 bar to 1600 bar at constant speed conditions to determine its performance metrics (i.e. Thermal Efficiency & Specific Fuel Consumption), combustion attributes (i.e. In-cylinder Pressure, In-cylinder Temperature & Apparent Heat Release Rate), and emissions characteristics (i.e. CO emission, Nox emission & Soot emission). In general, as injection pressure was raised, thermal efficiency, CO emissions, and soot emissions all improved, while in-cylinder temperature, in-cylinder pressure & NOx emissions rose progressively. For instance, for 1400 bar fuel injection pressure, maximum in-cylinder pressure and in-cylinder temperature were found, around 18.6 bar and 1650 K, respectively, whereas injection started at a 22-degree crank angle before top dead center (bTDC). The optimal injection pressure for internal combustion engines was determined by considering both emissions and performance. The results indicated that an injection pressure near 800 bar led to the following outcomes: an in-cylinder temperature of approximately 1520 K, an in-cylinder pressure of around 17.5 bar, a thermal efficiency of 32.50%, and a specific fuel consumption of approximately 292 g/KW-h. Additionally, implementing a 90%-10% split injection method with equal crank angle duration (CAD) resulted in an average reduction of 4-6% in NOx emissions.

Effect of Metal Filler on the Welded Joint of X70 Steel Joined to Duplex Stainless Steel by Gas Arc Welding

Zakaria Boumerzoug — 2025-03-20

This study investigates the effects of using two different metal fillers on the microstructure, corrosion resistance, and mechanical properties of a duplex stainless steel and X70 steel welded joint, performed using the Gas Tungsten Arc Welding (GTAW) process. The electrodes employed were ER2209 and ER70S. The research aims to assess the feasibility of welding dissimilar steels with these two electrodes. Three weld passes were conducted using the different electrodes, followed by characterization of the welded joint's microstructure and evaluation of its mechanical properties. The primary characterization techniques included optical microscopy, scanning electron microscopy, Electron Backscatter Diffraction (EBSD), corrosion testing, Vickers microhardness, and tensile testing. The welded joint exhibited no visible defects, and using two electrodes increased the hardness, particularly in the fusion zone, where it reached 290 HV. Microscopic analysis revealed a solidification microstructure in the fusion zone. The welded joint demonstrated intermediate corrosion resistance between the two base steels (duplex stainless steel and X70). At the same time, its tensile strength was also intermediate, achieving more than 96% of the nominal tensile strength of duplex stainless steel. This approach of bonding dissimilar steels offers a potential solution for substituting one steel type with another in automotive structures, enhancing their resistance and reducing production costs.

Preparation of Antifouling Composite Coating for Rubber. Part 1: Manufacturing and Laboratory Testing

Thanh Nguyen Trung — 2025-03-20

This article introduces results of investigations on Cu₂O concentration on release rate of antifouling composite coating for rubber, effects of fineness on ability to release Cu₂O of paint (fineness of paint increases, Cu₂O release speed of composite coating decreases), effects of period from composite coating preparation to start testing on ability of Cu₂O release. Besides, effects of anti-UV additive on ability of composite coating to withstand from UV-thermo-humidity complex was also investigated. Results show that Cu₂O concentration is 25 weight percent (wt. %), fineness of paint is 75-80 µm are suitable, period from composite coating preparation to time for being used is about 5 days for the best antifouling grade while ensuring mechanical properties of composite coating. Anti-UV additive of 1 wt. % is suitable for antifouling composite coating for rubber.