Applied Mechanics and Materials Vol. 895

Abstract: Green sand casting is treated as the most versatile casting process due to their excellent design flexibility that offer complex shapes and ability to reclaim silica sand. The modern foundries are looking for alternate moulding materials to partially replace the high cost silica sand. Cow dung is a naturally available eco-friendly binding as well as additive material and is used to partially replace the silica sand. Improper choice of the combination of moulding sand variables, such as degree of ramming, percentage of cow dung, percentage of clay, and percent of water will affect the moulding sand properties and thereby quality of casting. In the present work, Taguchi method is employed to plan and conduct experiments. Pareto analysis of variance is performed to know the contribution of variables on the moulding sand properties (i.e. compression strength, permeability, loss-on-ignition). Taguchi DEAR method is used to determine the single optimal levels of input factors that enhances the performances of all the sand mould properties. Percent of clay and cow-dung found to be the most dominating factor towards all the sand mould properties.

Abstract: Glass, being considered as hard and brittle material is very difficult to machine into desired shapes. The readily available conventional machining process does not provide good surface finish thus requires additional machining process. This paper reviews the different existing non conventional machining process accessible till today for the machining of glass materials. This paper also discusses the advantages and disadvantages of the existing non conventional machining processes. The various hybrid non conventional machining processes are also studied with focus on machining output characteristics like MRR, surface finish, tool wear rate. This paper summarizes the selection of hybrid non conventional machining processes for the various type of glass.

Abstract: Natural fibers, in particularly lignocellulosic fibers are attracting material scientists now days, due to their comparative advantages over synthetic fibers. Biodegradable composites reinforced with short banana fibre after alkali treatment along with cassava starch matrix were prepared using the hot compression method. The mechanical properties like tensile strength and impact strength were investigated. Mechanical properties of the composites made from alkali treated fibres were superior to the untreated fibres. SEM observations on the fracture surface of composites showed that the surface modification of the fibre occurred and improved fibre–matrix adhesion. Keywords: Surface modification; banana fiber; Biodegradable composites; Mechanical properties; Matrix.

Abstract: To be economical, enterprises confronting present intense and phenomenal worldwide business situations must plan and provide the best products and services and move forward their manufacturing maneuvers by typically utilizing Lean manufacturing practice. It is involved with converting materials into valued products by utilizing raw material to enhance productively and to maximize the benefit of an organization and minimize the waste. Green manufacturing is a strategy that reduces waste and contamination by the nonstop approach. This study points to examine the lean and green manufacturing concept and its integration in operation management. Operations management is a collective endeavor to adjust costs incurred with income to realize the most elevated networking benefit conceivable [1]. In this way, procedures of lean logic can play an incredible role. The present paper is a case study approach in the qualitative analysis of selected SMEs.

Abstract: In the present study an attempt has been made to investigate the effect of process parameters on surface roughness and cutting forces generation in machining of Duplex Stainless Steel (DSS 2205) grade material with TiN coated carbide tool. Taguchi technique is used for optimizing the process parameters. L₂₇ orthogonal array was used to conduct the experimental trials. Cutting forces recorded using piezo-electric based mill tool dynamometer and surface roughness measured using surface roughness measuring instrument. The obtained results indicated that the cutting force increases with increase in feed rate and depth of cut whereas cutting forces decreases with increase in cutting speed. Surface roughness decreases with increase in cutting speed and low feed rate. Scanning Electroscope Microscopic (SEM) images indicates the feed marks, undeformed material and patches on the machined surface. The formation of material side flow and burrs on the feed marks ridges observed at higher cutting speed, low feed rate and depth of cut. It is mainly due to the material behavior like elastic-plastic deformation of the surface layer. The material side flow causes the considerable deterioration of surface quality of the DSS 2205 steel.

Abstract: The traditional finishing processes are incapable of producing required surface finish and other characteristics in difficult-to machine materials like Nickel based superalloys and also complex geometrical shapes of engineering components. Hence to achieve these goals non-traditional micro-machining processes have been developed. Extrusion honing (EH) is one of the non-traditional micro-machining process to debur, radius, polish, and remove recast layer of components in a wide range of applications. In this process material is removed from the work-piece by flowing abrasive laden medium under pressure through or past the work surface to be finished. Components made up of complex passages having surface/areas inaccessible to traditional methods can be finished to high quality and precision by this process. Hastelloy C22 offers resistance to both aqueous corrosion and attack at elevated temperatures and it is a difficult metal to machine using traditional techniques. In this study, micro finishing of internal surface of Hastelloy C22 material having predrilled passage diameters 7, 8, 9 and 10 mm have been performed in an indigenously built hydraulic operated one way extrusion honing setup. For the present EH process, patented polymer mixed with SiC abrasive at 35% volume concentration was used as carrier medium. The study was performed for 46, 54, and 60 grit sizes of SiC abrasive. The material removal in EH process varies with passage diameter and grit size of abrasives at each trial. A feed forward back propagation neural network model has been developed for the prediction of material removal and it has successfully predicted material removed in each trial of EH process.

Abstract: This research work uncovers the wear performance of short glass fiber (SGF) fortified thermoplastic copolyester elastomer (TCE) hybrid composites loaded up with both micro (short carbon fibers, PTFE, SiC, Al₂O₃ and MoS₂) and nano(Al₂O₃ and PFPE) sized particulate fillers. The readied hybrid composites are tested for tribological performance using pin-on-disc test rig. Test outcomes uncovered that TCE hybrid composite strengthened with SGF and loaded up with PTFE, SiC, Al₂O₃ and MoS₂ displayed better wear resistance, however TCE hybrid composite loaded up with nanolubricating filler i.e. PFPE displayed slightest friction coefficient (μ) in the investigation. This study additionally archives the impact of tribological control factors such as sliding distance, sliding speed and filler content on tribological conduct of TCE composites in terms of specific wear rate (K_s) and μ.

Abstract: Natural fibers are widely used for reinforcement in polymer composite materials and proved to be effectively replacing synthetic fiber reinforced polymer composites to some extent in applications like domestic, automotive and lower end aerospace parts. The natural fiber reinforced composites are environment friendly, have high strength to weight ratio as well as specific strengths comparable with synthetic glass fiber reinforced composites. In the present work, hybrid epoxy composites were fabricated using calotropis procera and glass fibers as reinforcement by hand lay-up method. The fibre reinforcement in epoxy matrix was maintained at 20 wt%. In 20 wt% reinforcement of fibre, the content of calotropis procera and glass fibre were varied from 5, 10, 15 and 20 wt%. The dry sliding wear test as per ASTM G99 and three body abrasive wear test as per ASTM G65 were conducted to find the tribological properties by varying speed, load, distance and abrasive size. The hybrid composite having 5 wt% calotropis procera and 15 wt% glass fibre showed less wear loss in hybrid composites both in sliding wear test as well as in abrasive wear test which is comparable with 20 wt% glass fibre reinforced epoxy composite which marked very low wear loss. The SEM analysis was carried out to study the worn out surfaces of dry sliding wear test and three body abrasive wear test specimens.

Abstract: Tribotesting is necessary to understand the behaviour of the material under various operating lubrication conditions. This paper deals with the training of an artificial neural network (ANN) model with Bio-lubricant properties and machining conditions for prediction of surface roughness and coefficient of friction in Tribotesting by Tool chip Tribometer. Experimental results obtained from Tool chip tribometer for tested bio-lubricants are compared with those obtained by ANN prediction. A good agreement in results recommends that a well trained neural network is competent enough to predict the parameters in Tribotesting process.