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Friction Stir Welding Process
Published in Noor Zaman Khan, Arshad Noor Siddiquee, Zahid A. Khan, Friction Stir Welding, 2017
Noor Zaman Khan, Arshad Noor Siddiquee, Zahid A. Khan
Grinding: This stage involves coarse, medium, and fine grinding of the prepared samples. Initially, samples are grinded on belt grinder to remove the effect of WEDM from the weld surface and then fine grinding is done on metallurgical grinding and polishing machine. Each stage of metallographic sample preparation must be carefully performed; the entire process is designed to produce a scratch-free surface by employing a series of successively finer abrasives. The idea is to carefully move from one stage to the next where the abrasives become finer at each successive stage. Movement from one stage to the next should only proceed when all of the scratches from the preceding stage are completely removed. The pieces are wet grinded using 100, 200, 400, 600,800, 1000, 1200, 1500, and 2000 grit silicon carbide paper. Care must be taken to ensure that the grinding in stage is performed with a constant force and it should be done for a constant duration of time.
Traction performance modeling of worn footwear with perpendicular treads
Published in Tribology - Materials, Surfaces & Interfaces, 2023
Shubham Gupta, Subhodip Chatterjee, Ayush Malviya, Arnab Chanda
Progressive wearing of outsoles was performed to understand the effect of worn regions on the slip variables (i.e. ACOF and fluid pressure). Artificial wearing protocol was applied, which shortened the entire observation period for determining the treads’ lifetime performance as suggested by Chang et al. [30]. Outsoles were worn in three wear cycles namely, first, second, and third wear cycle which mimics the outsole topography of treads worn after 3 months, 6 months, and fully worn upto the outsole base material. The worn cycles were controlled based on a previous study by Hemler et al. [27] which simulated the wearing time based on the distance of abrasive belt grinder. Wearing of the outsoles were performed by attaching the developed outsoles beneath the footwear, placing the footwear at an angle of 17 ± 1° over the belt grinder (50 Grit, 3M Industries), and measuring the distances. The 17 ± 1° angle was based on previous studies [17,26] which considered this metric to wear the footwear. The outsoles were worn, worn burrs of outsole material were cleaned, and experimentally slip tested. Similar procedure was followed for the subsequent wear cycles. Figure S2 represents the worn outsoles after first, second, and third wear cycles whereas Figure 1 shows the consolidated images of an outsole (i.e. H6) after subsequent wear cycles.
Mechanical and tribological properties of LM13/TiO2/MoS2 hybrid metal matrix composite synthesized by stir casting
Published in Particulate Science and Technology, 2019
The specimen obtained was then ground in bench grinding machine to remove the burrs and polished in belt grinder for a rough surface finish, which were further polished using emery sheets of grit size 400, 600, 800, and 1000. After this process, fine polishing using disk polisher with diluted Al2O3 was performed to remove all the burrs and scratches on the surface to obtain a good mirror-like surface finish. The polished specimens obtained as per ASTM E3–11 standards were then etched with Kroll’s reagent (92 mL distilled water, 6 mL nitric acid, and 2 mL hydrofluoric acid) by swabbing 10–20 s before examination using Zeiss Axiovert 25 CA Inverted Metallurgical Microscope. The microstructural examination was then performed to observe the homogeneous distribution of the reinforcement particles in the composite matrix.
Assessment of white layer in hardened AISI 52100 steel and its prediction using grinding power
Published in Machining Science and Technology, 2018
Umamaheswari Madopothula, Ramesh Babu Nimmagadda, Vijayaraghavan Lakshmanan
WL thickness was measured using optical micrograph and scanning electron microscopy (SEM); Hardness variation was analyzed using Vickers micro-hardness tester and the distance between two indentations was well maintained to avoid over lapping as shown in Figure 2. X-ray diffraction (XRD) is used to analyze the phase transformation in WL. Power drawn by spindle motor was measured by using Hall Effect sensor in power meter to correlate the WL formation with power and the schematic for power measurement is shown in Figure 3. During grinding of work material, the power drawn by the spindle motor was monitored with a power meter and the data was collected continuously. This data was analyzed by means of LabVIEW 2012 software. This data was collected at 2 kHz sampling rate. The ground samples were carefully protected from rust formation after grinding. The grinding wheel images were captured using a Basler CCD camera at multiple locations to evaluate the wheel wear. To study the formation of WL, the samples S5, S10, S15, S20, S25, T1 ground with SG wheel, and the specimens A5, A10, A15, A20, A25, B1 ground with WA wheel were subjected to microstructural characterization. These samples were cut perpendicular to the ground surface with wire cut electric discharge machine as 5 mm × 5 mm × 5 mm. These samples were then finished with a belt grinder in order to remove the heat-affected zone/recast layer formed during cutting with wire cut electrical discharge machining (EDM). Then, all these samples were polished using standard metallographic procedure followed by optical microscopic examination of upper and sub-surface layers of ground surface. These samples were polished using emery papers of mesh size 400, 800, 1,200 and 2,000 followed by polishing using 6 µm alumina paste and final polishing is done using 0.5 µm diamond paste. The samples were then chemically etched using 2% nital solution (2 ml of nitric acid with 98 ml of ethanol) for 5s and the etched surface were observed under Quasmo MR 5000 (Quasmo, Haryana, India) inverted metallurgical microscope with polarised light source under bright field mode at a magnification of 200x. Similar sample preparation procedure is followed for samples used for SEM study. Micro-hardness was measured using Vickers hardness tester by applying 25 g load for 10 s duration. Five measurements were taken at each depth to minimize the error and the indentations are well spaced to avoid any overlapping.