Mechanical characterization and optimization of heat treatment parameters of manganese alloyed austempered ductile iron

Austempered Ductile Iron (ADI) belongs to the family of cast irons whose mechanical properties are altered using austempering heat treatment process. The objective of this paper is to study the effects of heat treatment parameters on manganese alloyed ADI. Hence, austenitization temperature, austempering temperature and austempering time are taken as the control variables along with the manganese content in the material. The effects of heat treatment are studied by measuring the ultimate tensile strength and the hardness of the material. The regression equations are developed to relate the various parameters under study. The microstructures of the specimen reveal that retained austenite content increases with increase in manganese and results in decrease in hardness of the material. The statistical analyses indicate that the austempering temperature is the major factor affecting the variation in hardness and tensile strength with 74.5 % of contribution within the range of values whereas, variation in manganese content does not have significant effect on hardness within the investigated composition range in the material

Experimental analysis of hardness and tensile characteristics of copper reinforced AA6061 stir cast composites subjected to thermal and deformation assisted heat treatments

AbstractAluminium alloy 6061 based composites reinforced with a varied weight percentage of copper particulates are fabricated utilizing a liquid metal stir casting technique. The collective influence of copper reinforcement, age hardening and low temperature thermomechanical treatment on AA6061 was investigated. The age hardened composites displayed better hardness and ultimate tensile strength than as cast composites. Thermomechanical treatment of the composites further enhanced the mechanical properties and hence showed better results over age hardened composites. The study revealed that an increase in the deformation enhanced the hardness and strength of the composite while the aging time to achieve the peak hardness was reduced. Both age hardened and thermomechanically treated composites with 6 wt.% copper reinforcement indicated the best peak hardness and UTS values at the lower aging temperature of 100 °C. The thermomechanically treated composite with 6 wt.% Cu, 15% deformation aged at 100 °C showed 80 and 69% increase in hardness and UTS, respectively, over as cast composite. Fracture surface analysis of the as cast, age hardened, and thermomechanical treated composites showed a mixed mode of fracture dominant with the brittle failure

Effect of Hybridization on the Mechanical Properties of Chopped Strand Mat/Pineapple Leaf Fibre Reinforced Polyester Composites

Hybridization of synthetic and natural fibres as reinforcement makes the polymer composites environmental friendly and sustainable when compared to synthetic fibres based polymer composites. In this study chopped strand mat/pineapple leaf fibres were hybridized. Four laminates with six layers each, with different stack sequence (GGGGGG, GPPPPG, PGGGGP and PPPPPP) were fabricated using hand layup technique while maintaining a fibre to matrix ratio of 30:70 by weight with polyester resin as matrix. Mechanical properties such as tensile and flexural strength were determined and morphology of fractured specimens was studied. Maximum tensile strength of 180 MPa was obtained for the laminate with six layers of chopped strand mat followed by hybrid laminate with four layers of chopped strand mat at the centre (120 MPa). Tensile strength of hybrid laminate with four layers of pineapple leaf fibres at the centre was in third position at 86 MPa. Least tensile strength of 65 MPa was obtained for the laminate with six layers of pineapple leaf fibres. Similar trend was observed in case of flexural behaviour of the laminates with maximum flexural strength of 255 MPa and minimum flexural strength 107 MPa. Scanning electron microscopy of the fractured specimen reinforced with chopped strand mat only, indicated, fibre pull out, matrix cracking and lack of matrix adhesion to fibres. In case of hybrid composite (GPPPPG and PGGGGP) delamination was observed to be prominent due to improper wetting of the pineapple leaf fibres with the matrix. More significant delamination led to lesser strength in case of pineapple fibres reinforced composites even though the fibre pull out was relatively less

Effect of Hybridization on the Mechanical Properties of Chopped Strand Mat/Pineapple Leaf Fibre Reinforced Polyester Composites

Hybridization of synthetic and natural fibres as reinforcement makes the polymer composites environmental friendly and sustainable when compared to synthetic fibres based polymer composites. In this study chopped strand mat/pineapple leaf fibres were hybridized. Four laminates with six layers each, with different stack sequence (GGGGGG, GPPPPG, PGGGGP and PPPPPP) were fabricated using hand layup technique while maintaining a fibre to matrix ratio of 30:70 by weight with polyester resin as matrix. Mechanical properties such as tensile and flexural strength were determined and morphology of fractured specimens was studied. Maximum tensile strength of 180 MPa was obtained for the laminate with six layers of chopped strand mat followed by hybrid laminate with four layers of chopped strand mat at the centre (120 MPa). Tensile strength of hybrid laminate with four layers of pineapple leaf fibres at the centre was in third position at 86 MPa. Least tensile strength of 65 MPa was obtained for the laminate with six layers of pineapple leaf fibres. Similar trend was observed in case of flexural behaviour of the laminates with maximum flexural strength of 255 MPa and minimum flexural strength 107 MPa. Scanning electron microscopy of the fractured specimen reinforced with chopped strand mat only, indicated, fibre pull out, matrix cracking and lack of matrix adhesion to fibres. In case of hybrid composite (GPPPPG and PGGGGP) delamination was observed to be prominent due to improper wetting of the pineapple leaf fibres with the matrix. More significant delamination led to lesser strength in case of pineapple fibres reinforced composites even though the fibre pull out was relatively less

Dependence of pre-treatment structure on spheroidization and turning characteristics of AISI1040 steel

AbstractDuring machinability, the combination of machining process parameters and the material properties of the component to be machined plays an important role. Material properties depend upon the type of phase form present and the grain size of the formed phases, which in turn depends upon the prior treatment given to alter the initial room temperature types and form. Accordingly, spheroidization treatment was carried out on medium carbon steel (AISI1040) by altering the initial room temperature structure through normalizing and hardening treatment. Machinability experiments were performed on CNC machine by varying machining process constraints. Tool wear and surface roughness of the machined component obtained by turning were analyzed and correlated. Using Minitab and full factorial design, the ANOVA study was carried out. With the help of regression analysis, residual and main effect plots combined optimization (tool wear and surface roughness) was targeted. ANOVA result shows excellent machinability for the as-bought-spheroidized condition where feed has a 67% contribution to tool wear (TW) whereas the depth of cut has a 71.91% contribution to surface roughness (SR). Also, the optimized regression values obtained for machining parameters are feed (0.39 mm/rev), depth of cut (0.6 mm), and spindle speed (780 rpm) with composite desirability of 0.8174. TW and SR experimental values for the optimized machining parameters are 0.039 mm and 2.89 μm, respectively, and the difference between the actual and optimized values is less than 5%

Abstracts of National Conference on Research and Developments in Material Processing, Modelling and Characterization 2020

This book presents the abstracts of the papers presented to the Online National Conference on Research and Developments in Material Processing, Modelling and Characterization 2020 (RDMPMC-2020) held on 26th and 27th August 2020 organized by the Department of Metallurgical and Materials Science in Association with the Department of Production and Industrial Engineering, National Institute of Technology Jamshedpur, Jharkhand, India. Conference Title: National Conference on Research and Developments in Material Processing, Modelling and Characterization 2020Conference Acronym: RDMPMC-2020Conference Date: 26–27 August 2020Conference Location: Online (Virtual Mode)Conference Organizer: Department of Metallurgical and Materials Engineering, National Institute of Technology JamshedpurCo-organizer: Department of Production and Industrial Engineering, National Institute of Technology Jamshedpur, Jharkhand, IndiaConference Sponsor: TEQIP-