In recent years, increasing demand for biodegradable lubricants has been observed in precision machining owing to ISO 14000, which draws more attention toward the operator’s health and environmenta...

Application of eco-friendly lubricants in sustainable grinding of die steel

Grinding is a manufacturing process which significantly contributes in producing high precision and durable components required in numerous applications such as aerospace, defence and automobiles. This review article is focused to uncover history, witness the present and predict the future of the grinding process. While going through the literature, it has been observed that minimal work has been done in explaining the history, present status and future scopes of the grinding process. In this era of information and environmental awareness, sustainability aspects have become a primary concern of almost every research field. In the grinding process too, the research work includes ecological elements such as reducing the consumption of cutting fluids through minimum quantity lubrication, utilizing cryogenics, hybrid lubrication and cooling techniques that are still required to be explored critically. Further, some significant findings of the prevailing research in grinding include modification in grinding wheel surface, merging different grinding principles such as usages of the textured grinding wheel, ultrasonic grinding, 3D printing of grinding wheel and artificial intelligence in grinding are also presented. Another unascertained problem is the management of grinding swarf, which is being attended to by recycling it to fabricate composites which is expected to be another prominent domain of research. Further, the advancements taking place exhibit the potential of the grinding process, suggesting that its future is bright and ever-growing.

A comprehensive review on the grinding process: Advancements, applications and challenges

The present work elucidates the compaction and the densification behavior of iron powder and coal fly ash (CFA) mixtures during powder metallurgy (P/M) processing. The flowability and the compressibility characteristics of the starting materials were exhibited through Hausner ratio and Carr’s index. Morphological, elemental and crystallographic characterizations of the starting materials were carried out using scanning electron microscopy (SEM), energy-dispersive x-ray spectroscopy and x-ray diffraction investigations, respectively. The CFA of 0, 5, 10 and 15 wt.% was mixed with the iron powder through ball milling. Further, the cold compaction of the mixtures containing iron/CFA was performed in the hardened steel die using a uniaxial hydraulic press at pressures of 91 MPa, 138 MPa and 185 MPa, respectively. Subsequently, the preforms were sintered at 950, 1050 and 1150 °C in a tubular furnace under an inert atmosphere. The density of the preforms and the sintered pallets was estimated using weight to volume ratio and Archimedes method, respectively. The obtained mineralogy, morphology and physio-mechanical properties of the CFA are in good agreement with the ASTM standards. Further, the flowability and the compressibility characteristics of the starting materials rendered them suitable for processing through the P/M process. SEM analysis of the sintered pallets exhibited uniform distribution of CFA particulates in the iron matrix with clear and strong interfaces. An inverse effect of an increased amount of CFA inclusion has been observed on the green and sintered density of the composite. However, a linear influence of increased compacting pressure and sintering temperature has been observed on green and sintered densities, respectively. The magnitude of the green density achieved during cold compaction is considerably higher than that achieved during the sintering process. The obtained compaction data were successfully fitted using the Ge compaction equation.

Compaction and Densification Characteristics of Iron Powder/Coal Fly Ash Mixtures Processed by Powder Metallurgy Technique

Nowadays, solar cell technology that dominates the market is a silicon-based solar cell with efficiency of 15-20%. Unfortunately, this type of solar cell has some weaknesses such as complex production process, utilize hazardous compounds and expensive production price. Therefore, the researchers developed organic solar cell namely dye-sensitized solar cell (DSSC). Nevertheless, the efficiency of DSSC still lower than that of conventional solar cell. Several studies have been carried out to increase the efficiency of DSSC like the use of anthocyanin dye. Anthocyanin is a flavonoid compound that has a wide absorption range and has conjugated π bond to catch photons from sunlight. The use of anthocyanin in DSSC has been applied in several methods, such as the use of single anthocyanin dye, adding copigment, and mixing them with other dyes. The purposes are to increase stability and widen light absorption area due to result in better efficiency. This article reviews the development of anthocyanin utilization as a natural dye in DSSC fabrication as well as some modifications that have been done. The use of anthocyanin as a natural dye in DSSC fabrication is feasible to be developed in industrial scale.

Anthocyanin as natural dye in DSSC fabrication: A review

Aircraft component manufacturing sector is looking for high precision machining in aircraft components. The present work explores the operability of green manufacturing of Nimonic C263 using dry tu...

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Experimental Study on Surface Roughness and Flank Wear in Turning of Nimonic C263 under Dry Cutting Conditions

The present work is aimed to explore the microstructural and mechanical characteristics of coal-fly ash reinforced iron metal-matrix composites (IMMCs), synthesized through powder metallurgy technique. Coal-fly ash wt%, compacting load and sintering temperature were considered as the input variables, whereas sintered density and microhardness of the composites were taken as the output responses. Flowability and compressibility of the starting materials were demonstrated using Hausner ratio and Carr’s index. Decorous morphological, crystallographic and elemental characteristics of the starting materials and IMMCs were deliberated using Scanning electron microscopy, X-ray diffraction and Energy-dispersive X-ray spectroscopy investigations respectively. A significant improvement in the microhardness of IMMCs by 50% and drop in density by 35% were found at 15 wt% as compared to 0 wt% reinforcement. The substantial increase in the microhardness eventually resulted in an increase in their specific microhardness by a factor of two. 
Significant improvements in the microhardness of IMMCs at 15 wt % of reinforcement, compacted at 10 ton and sintered at 1150°C were found to be prompted by the strengthening mechanisms like load transfer, Hall–Petch effect and Taylor strengthening. The analytically calculated microhardness in the light of strengthening mechanisms was found smaller than the corresponding experimental values as a function of wt % of reinforcement. Further, statistical analysis of the obtained results was carried out using response surface methodology.

Investigations on microstructural and microhardness developments in sintered iron–coal fly ash composites

To comply with the remarkable demand of bio-implants at a reasonable cost, selection of appropriate material, efficient manufacturing processes and associated parameters play a vital role. Particularly, benign of green manufacturing is gaining huge attention in bio-implants manufacturing to comply with environmental concerns. The present work is an effort to exhibit the viability of green manufacturing during dry turning of bio-implant steel (AISI 316L) using coated carbide cutting tool. Cutting speed, feed rate, depth of cut and tool nose radius are considered as input variables, whereas main cutting force, tool flank wear and centreline mean surface roughness are taken as output responses. Range of the input variables has been decided on the bases of pilot studies. Using the design of experiment strategy, experimentation has been carried out on a computerized numerically controlled lathe machine in a dry environment. Significant input variables affecting the responses have been identified through the analysis of variance and response surface methodology. Further, mathematical regression models have also been derived. Desirability factor-based multi-response optimization analysis has been implemented and found the optimum main cutting force: 113.6 N, flank wear: 0.14 mm and mean surface roughness: 1.27 µm, at cutting speed: 125 m/min, feed: 0.05 mm/rev., depth of cut: 0.75 mm and tool nose radius: 0.4 mm.

Amarjit Singh

Papers

Investigations on microstructural and microhardness developments in sintered iron–coal fly ash composites

Compaction and Densification Characteristics of Iron Powder/Coal Fly Ash Mixtures Processed by Powder Metallurgy Technique

Multi-Response Optimization During Dry Turning of Bio-implant Steel (AISI 316L) Using Coated Carbide Inserts