[en] Experiments were conducted on Ti-6Al-4V alloy using abrasive water jet machining (AWJM) by varying process parameters such as water jet pressure, stand-off distance and abrasive flow rate. Surface integrity characteristics like surface roughness, surface hardness and microstructural evolution were studied. Effect of machining parameters on the surface and sub-surface hardness was determined. The grain size distribution, phase fractions, grain boundary deformation and grain boundary misorientation angle of the machined titanium (Ti6Al4V) alloy were studied using electron backscattered diffraction (EBSD) images. XRD images of machined Ti-6Al-4V samples were utilized to assess the peak shift and formation of new phases such as oxides. Crystallite size, dislocation density and lattice strain of the machined samples were evaluated using XRD results. Average grain size, mis-orientation angle, α and β phase fraction were evaluated with respect to AWJM parameters. (paper)

[en] The objective of this research work is to study the impact of graphite forms used as solid lubricant additives on brake friction materials performance. Three composites were fabricated using the conventional process and were characterised for its physical, chemical, mechanical and thermal properties conforming to industrial standards. The thermal stability of the graphite particles and developed composites was measured in an air atmosphere using the thermogravimetric analyser. The tribological performances were studied using the Chase friction test machine as per IS-2742 Part-4 standard. The results indicated that the friction composite containing expandable graphite exhibited better thermal stability with good fade and recovery performances. This led to enhance wear resistance and stable friction due to its better heat dissipation and lubricity comparing with the other two composites. An empirical relationship for the friction and wear was developed based on Chase test results. The worn surface morphologies of the Chase tested composites were analysed using scanning electron microscopy to study the sensitivity of the friction–wear mechanisms to the graphite-type effect.

[en] Lubrication and abrasiveness in the brake friction composites are imperative characteristics for the better tribological performance at elevated temperature conditions. The present study aims to develop brake friction composites by conventional manufacturing processes in the form of standard brake pads using iron sulfide as a solid lubricant with a synergistic effect of red mud as an abrasive. Three different brake friction composites were developed by varying key ingredients such as red mud and iron sulfide by keeping other parental ingredients as constant. The developed composites were subjected to experimentation for physical, chemical, mechanical and thermal properties in accordance with industrial standards. The tribological performance was analyzed experimentally using Chase friction test rig according to IS2742 part-4. From the experimental work, it can be concluded that the synergetic effect of red mud and iron sulfide particles in friction composites showed stable fade and recovery behaviors, while the iron sulfide-based friction composites showed lesser wear rate. Scanning electron microscopy (SEM) of the Chase tested friction composites showed the surface characteristics of the composites. (paper)

[en] The present study deals with the characterization of fibers extracted from a weed plant known as Impomea pes-caprae. The fibers were collected, processed and chemically treated with benzoyl chloride solution. The raw and benzoyl chloride treated fibers were characterized for its physical, chemical, crystalline, thermal, and morphological characteristics using tests namely chemical analysis, XRD, FTIR, thermogravimetric analysis and scanning electron microscopy. To prove its application suitability, raw and chemically treated Impomea pes-caprae fibers based epoxy composites were developed using hand lay-up process and analyzed for its mechanical characteristics as per American Society for Testing and Materials. The stress distribution in the tensile and flexural tested composites was analyzed analytically using ANSYS software, and the significant difference between the samples was studied using ‘One-way ANOVA’. The results showed that the benzoyl chloride treated Impomea pes-caprae fibers, and its composites showed improved results in all its performance characteristics. (paper)