Enhancing mechanical and structural properties of pewter alloy using microwave sintering

97%Sn 2%Cu 1%Sb (pewter) alloys were examined to determine the effect of green density, sintering time and sintering temperature on the mechanical and structural properties of the conventional and microwave sintered compacts. Two compaction loads; 30kN and 40kN were used to produce the samples with different green densities. Eight different time-temperature combinations were used for each heat treatment. Samples with a higher green density resulted in a higher sintered density and higher hardness. Longer sintering time and higher sintering temperatures resulted in higher densities, larger grain size and higher hardness for both sintering methods. However, the microwave sintered samples in general have finer microstructures, higher densities and higher hardness compared to the conventional sintered samples in a much shorter duration. Better mechanical and structural properties were achieved by microwave sintering in 15 minutes compared to conventional sintering which took 120 minutes

Mechanical and Structural Properties of Microwave Sintered Tin-Copper-Antimony Alloys

Tin-copper-antimony (pewter) alloys have been traditionally produced by a casting process which consumes large amounts of energy, time and as a result is expensive. This research aims to investigate the possibilities of implementing powder metallurgy for pewter production through a sintering process using microwave energy. The optimum sintering conditions using microwave sintering are also of interest. Pewter alloys were examined to determine the effect of green density, sintering time, and sintering temperature on the mechanical and structural properties of the sintered compacts. Samples were prepared by hydraulic pressing of a well mixed and blended tin alloy powder with three different compositions; 97wt%Sn 2wt%Cu 1wt%Sb, 94wt%Sn 4wt%Cu 2wt%Sb and 91wt%Sn 6wt%Cu 3wt%Sb. Two compaction loads were used to produce the samples with different green densities. Pellets pressed at 96 MPa had an average relative density of 80.7%, while those pressed at 129 MPa had an average green density of 84.6%. Sixteen different time-temperature combinations were used for the heat treatments at 160 and 220 C for both conventional and microwave sintering. However, the sintering times had to be restricted to 15 and 30 minutes for microwave heating. Meanwhile, 60 and 120 minutes were used for conventional heating. It was found that for all three compositions, samples with a higher green density had a higher sintered density, compared to samples with lower green density, for the same sintering time and temperature. The relative density of sintered pewter alloys increased on average by 13% after conventional sintering and by about 14% after microwave sintering, when the sintering was carried out for the longer of the two sintering times and at the higher of the sintering temperatures selected, for all three compositions. Moreover, the hardness increased by 25.6%, 23.5% and 7.0% when microwave sintered relative to the conventional sintering for 97Sn2Cu1Sb, 94Sn4Cu2Sb and 91Sn6Cu3Sb alloys respectively. Nevertheless, the grain size remained similar for all three compositions under the same sintering conditions. The degree of grain growth in microwave sintered samples was marginally smaller (up to 23-24 μm) than in conventionally sintered samples which reached a grain size of 26-27 μm. In terms of strength, microwave sintering produced samples with similar properties to those conventionally sintered under the same sintering conditions for all three compositions. The tensile strengths obtained compared well with the strengths obtained from the casting process. Nonetheless, tensile strengths for both conventionally and microwave sintered material was higher in the transverse direction than in the longitudinal direction. In conventionally sintered material, there was an increase in transverse strength of about 6.9%, 5% and 4%, while for the microwave sintered material, the strength increase was 9.1%, 5.6% and 4.5% for 97Sn2Cu1Sb, 94Sn4Cu2Sb and 91Sn6Cu3Sb alloys respectively when compared to the longitudinal direction. The microwave sintered samples in general have improved hardness, better densification and a finer microstructure compared with the conventionally sintered samples and traditionally cast pewter. Increasing the Cu and Sb content increases the hardness and strength but in return, decreases its ductility. Hence, a pewter alloy with a moderate amount of Cu and Sb, i.e. 97Sn2Cu1Sb, microwave sintered at 220 C for 30 minutes would be the best choice for optimum mechanical properties

Effect of microwave sintering on the mechanical and structural properties of pewter alloy

97%Sn 2%Cu 1%Sb (pewter) alloys were examined to determine the effect of green density, sintering time and sintering temperature on the mechanical and structural properties of the conventional and microwave sintered compacts. Two compaction loads; 30kN and 40kN were used to produce the samples with different green densities. Eight different time-temperature combinations were used for each heat treatment. Samples with a higher green density resulted in a higher sintered density and higher hardness. Longer sintering time and higher sintering temperatures resulted in higher densities, larger grain size and higher hardness for both sintering methods. However, the microwave sintered samples in general have finer microstructures, higher densities and higher hardness compared to the conventional sintered samples in a much shorter duration. Better mechanical and structural properties were achieved by microwave sintering in 15 minutes compared to 120 minutes by conventional sintering

Economic analysis of using e-glass composite wrap repair system for pipelines in Malaysia

One of the biggest problems faced by the oil and gas industries is transmitting gas when there is a damaged pipeline. This damage may be a result from corrosion, crack or a burst pipe. Damaged pipelines need a safe, quick and efficient repair mechanism to prevent any further extensive damage. There are various methods and repair systems that offer different advantages and limitations to the oil and gas industries. Composite wrap repair system is a new technology that is being used in the United States of America and some European countries. However, this technology has not penetrated into the South East Asian region yet. This study is done with the aim of determining the feasibility of implementing this repair system into the Malaysian oil and gas industries. E-Glass fiber was selected since it is the most suitable and appropriate type of composite that can be adapted for the composite wrap. Then, cost analysis was done for this composite repair system and compared with the welding repair and pipeline replacement methods. Calculations for the result of every repair system were performed to compare the most efficient method. E-Glass fiber composite wrap has shown to be the most economical technique when compared with the welding and pipe replacement methods

Wear analysis of titanium carbonitride in machining high strength steel (KRUPP 6582) using used palm oil as cutting fluid

Palm oil is organic and completely harmless to human and the environment. It is a greener alternative to synthetic oil. Moreover, it has good lubrication properties due to its polar nature. Used cooking oil is usually discarded into the drain and contribute to the clogging in the drain and water pollution. Otherwise, it is ended up in the landfill in a plastic container or plastic bag. Reusing cooking oil is part of circular economy and does to some extent reduce the burden onto the environment. Clean unused palm oil and used palm oil are used as cutting fluid in the machining of high strength steel (KRUPP 6582) using Titanium Carbonitride (TiCN) coated tool in turning process. Analyses on the tool wear, tool life, cutting forces, material removal rate (MRR) and cost are performed. Three different cutting speeds are employed: 194, 245 and 305 m/min with depth-of-cut (0.2 mm) and feed rate (0.1 mm/rev). Used palm oil has shown significant decrease in wear rate by 5.9, 8.8 and 9.5% when machining at 194, 245 and 305 m/min respectively. Using used palm oil has shown increment in tool life and total volume removal of material by 12%, 55% and54% when machining at 194, 245 and 305 m/min respectively. Used palm oil results in a cheaper and more economical option as a cutting fluid since there can be savings up to 17.7-20.7%