Due to the complexity of controlling parameters in carburization, there has been relatively little work on process variables during the surface hardening process. This work focuses on the effects of the carburizing temperature and time on the mechanical properties of mild steel carburized with activated carbon, at 850, 900 and 950 ºC, soaked at the carburizing temperature for 15 and 30 minutes, quenched in oil, tempered at 550 ºC and held for 60 minutes. Prior carburization process, standard test samples were prepared from the as received specimen for tensile and impact tests. After carburization process, the test samples were subjected to the standard test and from the data obtained, ultimate tensile strength, engineering strain, impact strength, Youngs' moduli were calculated. The case and core hardness of the carburized tempered samples were measured. It was observed that the mechanical properties of mild steels were found to be strongly influenced by the process of carburization, carburizing temperature and soaking time at carburizing temperature. It was concluded that the optimum combination of mechanical properties is achieved at the carburizing temperature of 900 ºC followed by oil quenching and tempering at 550 ºC

The use of environmentally friendly materials for industrial applications has increased tremendously in the past decades due to environmental concerns associated with using synthetic materials. The present comparative investigation studied the properties of raw and chemically-treated coconut shell biomass for possible polymeric composite applications. The coconut shell biomass was treated with alkali (NaOH), bleaching and combined NaOH-bleaching solutions and investigated the surface morphology, chemical transformations, and thermal stability. Untreated and chemically modified coconut shell biomass was characterized through the determination of chemical constituents, X-ray diffraction (XRD), Fourier Transform infrared spectroscopy (FTIR), thermogravimetric (TGA), and morphological analyses.

Determination of work index of graphite from Samanburkono (Nigeria) using modified bond's method

Effects of titania (TiO₂) and silicon carbide (SiC) on phase development and physico-mechanical properties of mullite-carbon were investigated. Powdered clay, kaolinite and graphite of predetermined compositions were blended with additives using ball mill for 3 h at 60 rev/min. Samples were produced by uniaxial compression and sintered between 1400°C and 1600°C for 1 h. They were characterized for various properties, phases developed and microstructural features. The addition of TiO₂ and SiC in the sample lead to the formation of TiC in the sample at 1400°C and 1600°C. This takes place through high-temperature solid-state reaction (reaction sintering) of TiO₂ and SiC. This also contributes to the reduction in the apparent porosity of the sample with increased sintering temperature. The presence of titania in the sample does not favour the stability of anorthite beyond 1400°C. The formation of 50.6% mullite in the sample at 1500°C made it have the highest cold crushing strength and absorbed energy. Young’s modulus of the sample increased with increased sintering temperature. The sample sintered at 1500°C is considered optimum.