Abstract: This paper studied chip morphology in end milling of aluminium alloy 6061 by various cutting parameter such as feed rate, cutting speed and depth of cut. Slot milling operation were conducted. The analysis consists of chip morphology, chip weight, chip thickness and chip length. Scanning Electron Microscope (SEM) were used to obtain and examine the chips. Result shows that, end milling with higher cutting speed, feed rate and depth of cut generated short, small and light weigh of chips.
Abstract: One of the major challenges in the fabrication of glass-metal Joint is the wettability of glass sealant over the metal surface. The aim of the work was to study the wetting and spreading behavior of borosilicate glass sealant over austenitic stainless steel SS 304 and copper substrates with different surface roughness and oxidation conditions. During the wettability study of borosilicate glass sealant over the metal specimen, glass pallets were melted over the different oxidized metal specimens. The wetting behavior of borosilicate glass over metal specimen was measured in terms of contact angle and spreading area. The types of oxide and change in microstructure after oxidation were examined with the help of XRD analysis and optical microscopy. Tensile strength and hardness of the metal substrates after oxidation was also evaluated .
Abstract: In order to fabricate the micro cavity with complex structure on stainless steel, the technology of micro electrochemical machining based on surface modification by fiber laser is adopted. Heating scan on the surface of 304 stainless steel by using fiber laser can realize marking. In the process of laser heating and metal melting on the surface of 304 stainless steel, oxide layer can be formed and phase transformation can also occur, and the corrosion resistance layer with predefined pattern is formed. In the next process of micro electrochemical machining, the laser masking layer severs as the protective layer to realize micro machining of micro cavity. A newly developed device of electrochemical micro machining based on surface modification by fiber laser can meet the micro machining requirement. After laser masking processing through laser scanning on the surface of the 304 stainless steel, the passivation electrolyte and high-frequence-pulse electrochemical machining power supply were adopted, and the samples with typical structures by using electrochemical micromachining with fiber laser masking were fabricated.
Abstract: The detour effect and Joule heating of electropulsing is employed on crack arrest. With respect to Inconel 625 alloy, the relationship between discharge parameters and the area of fusion zone, microstructure around the crack tip and mechanical properties are studied. The experimental results indicate that the area of molten hole is directly proportional to the electric energy input. The microstructure ahead of the crack tip is refined and uniform with the increase of electric energy input. The optimum discharge parameter range, which contributes to the improvement of comprehensive mechanical properties, can be obtained.
Abstract: Machining parameters is a main aspect in performing turning operations using lathe machines. Cutting parameters such as cutting speed, feed rate and depth of cut gives big influence on the dynamic behavior of the machining system. In machining parts, surface quality and tool wear are the most crucial customer requirements. This is because the major indication of surface quality on machined part is the surface roughness and the value of tool wear. Hence, to improve the surface roughness and minimize the forming of tool wear, the optimum feed rate and cutting speed will be determined. The input parameter such as cutting speed, feed rate and depth of cut always influence the tool wear, surface roughness, cutting force, cutting temperature, tool life and dimensional accuracy. The D2 steel was being investigated from the perspective of the effect of cutting speed and feed rate on its surface roughness and tool wear. The results show that cutting speed is the main parameter which affects the surface roughness where the most optimum parameter would be at cutting speed of 173, 231 and 288 m/min with feed rate of 0.15 mm/rev. The tool wear strongly affected by feed rate where at 0.15 mm/rev the tool wear value is the lowest. The combination of high cutting speed and low feed rate was the best parameter to achieve smooth surface roughness.
Abstract: This paper explains the type of heat treatments used to improve the bulk hardness and tensile properties of Tungsten Inert Gas (TIG) welded Al6061-SiC reinforced composites. Composites with 8, 10 and 12 wt% of SiC (25 μm) are TIG welded using ER5356 filler material and the hardness, tensile property and microstructural analysis in as weld condition is carried out. Age hardening heat treatment is performed and peak hardness values are noted at different aging temperatures and subjected to characterization. Al6061-12 wt% SiC shows reduction in tensile strength in comparison with the other two in spite of improvement in hardness. Since hardness is more, there arise ambiguity in knowing the actual cause of decrease in the tensile strength. Optical micrographs of the samples are taken and identified the presence of dendritic segregation as the actual cause for the (UTS) reduction. To remove dendritic segregation, all the as weld samples are subjected to 5h homogenizing at 500°C, age hardened and characterized. The result showed substantial hike in UTS with substantial improvement in hardness, homogeneous distribution of hardness over the cross-section in the weld bead. The depth and distribution of hardness and bulk property improvement are observed by the combined effect of homogenizing and low temperature age hardening.
Abstract: Nowadays natural fiber and polymer matrix are being extensively used as alternatives in producing furniture like ceiling, floor and etc. to fulfill society demand instead of environmental friendly and saving cost. The objective of this study is to investigate the effects of maleic anhydride grafted polypropylene (MAPP) as a coupling agent for reinforcement between kenaf fiber (KF) and polypropylene (PP). The ratio of MAPP between 3% and 5% was observed to determine which composition ratio is better. The tensile strength for both 30% KF and 40% KF was treated through the alkali treatment process with 5% sodium hydroxide (NaOH). Kenaf fiber reinforced polypropylene (PP/KF) composites were melt blended and then used hydraulic molding test press machine for characterization to observe their tensile strengths by measuring their threshold. Tensile test was carried out to determine the tensile stresses of the composite at the best composition ratio of kenaf fiber that are 30% KF and 40% KF instead of MAPP ratio. The result shows 40% KF (5% MAPP) lead to better tensile performance compared to 40% KF (3% MAPP), 30% KF (5% MAPP) and 30% KF (3% MAPP). Meanwhile, Scanning electron microscopy (SEM) is used to observe the morphological comparison between untreated KF and treated KF as well as PP/KF. The good interfacial bonding between KF and PP was 5% MAPP rather than 3% MAPP due to the optimum strength received. Overall 5% MAPP with 40% PP/KF had shown the best result compared to others with the estimated tensile strength value of 21.38 MPa.
Abstract: Magnesium alloys, in which the in-situ Mg2Si particles were dispersed, were fabricated by a casting process, and the dry sliding wear behavior of the alloys was investigated. Optical microscopy revealed that the polygonal Mg2Si particles were homogeneously dispersed in the alloys. Mg2Si particle volume fractions in the alloys were 7 and 11 vol%. Although the wear loss of the alloy decreased due to the particle-dispersion, there was no difference in the wear loss between the alloys with different volume fractions. The worn surfaces of the particle-dispersed alloys were covered with the crumbled Mg2Si particles, which would prevent seizure between the alloy and the steel counterpart, leading to an improvement in the wear resistance of the alloy. The particle-dispersion slightly decreased the scatter of the coefficient of friction during the wear for the low sliding speed and load, but the effect of the dispersion was not clearly observed for the high speed and load.
Abstract: After the adverse effects of asbestos used in brake shoes on vehicles were come up, the researches on ecological shoe material have been carried out by many researchers. From this point forth, four different twaron-reinforced composite materials, which could be brake shoes, were produced in this study. Samples were produced in double acting press at a pressure of 100 MPa at 160°C by mixing the components used in powder form in a mixer. The samples were cured at 160°C for 6 hours. After curing, produced samples and those taken from commercial shoes were compared by performing hardness pin-on-disc wear tests (ASTM G99-95). When the results are evaluated in terms of hardness, it was observed that 20% twaron-reinforced sample has the highest hardness (116,88 Rockwell-R), but when evaluated in terms of friction, it was seen that while 5% twaron-reinforced sample satisfies highest friction coefficient, 10% twaron-reinforced sample exhibits close values to the commercial brake shoe at varying loads and showed a stable friction performance.
Abstract: This work is devoted on the synthesized new hybrid nanocomposite materials by using mechanical stirring method through a combination of different types of material; epoxy based matrix and nanofiller (TiO2 nanoparticles) as a reinforcement material. In additional this paper studies the effect of TiO2 nanoparticles with percentage 2-8 wt% added to epoxy based matrix on the mechanical properties (tensile properties and hardness property). The results showed that the tensile strength of nanocomposite material increased gradually by increasing the weight percentage of TiO2 nanoparticles from 2 wt % to 8 wt % TiO2, while the best tensile strength was at 8 wt % TiO2. The maximum value of tensile strength was 270% higher than the neat epoxy matrix. The hardness increase gradually with increasing percentage of TiO2 nanoparticles from 2wt% TiO2 up to 8wt% TiO2, the maximum value of hardness was at 8wt % TiO2, so the hardness of nanocomposite is around 86% higher than the neat epoxy matrix.