Uttam Kumar Debnath

The Experimental Characteristics and Evaluation of Nylon-12 in Erosion Process

Polymer materials are used in a wide range of applications. The erosion properties of nylon-12 were analyzed in this study. Randomly-shaped sand (SiO2) particles of various sizes (300–355 lm, 355–500 lm, and 500–600 lm) were selected as erosive elements. Impingement angles between 15 and 90_, impingement velocities between 30 and 50 m/s, and stand-off distances 15–25mm at ambient temperature were tested. During testing, the maximum erosion of the tested polymer composite occurred at 30_ angle of impingement, indicating a ductile nature of the test material. Erosion increased with impact velocity and decreased with stand-off distance. The erosion rate varies from approximately 5 to 1600 mg/kg at different combinations of impact velocity, impact angle, and other related parameters. The mean S/N ratio was found to be _41.35 dB, which reflects the average erosion rate under different test conditions. Test results were evaluated using Taguchi’s concept to minimize the observations needed, and analysis of variance (ANOVA) was used to identify interactions between tested parameters and identify the most significant parameters. Surface damage was examined using scanning electronic microscopy (SEM) to examine the nature of the wear behavior. The morphology of tested material showed micro cutting, micro cracking, ploughing, and deformation as dominating damage characteristics of impacting surfaces.

Experimental Evaluation of Erosion of Gunmetal under Asymmetrical Shaped Sand Particle

The erosion characteristics of gunmetal have been evaluated practically at different operating conditions. Asymmetrical silica sand (SiO2) is taken into account as erodent within range of 300–600 μm. The impact velocity within 30–50 m/sec, impact angle 15–900, and stand off distance 15–25 mm are inspected as other relevant operating test conditions. The maximum level of erosion is obtained at impact angle 15° which indicates the ductile manner of the tested gunmetal. The higher the impact velocity, the higher the erosion rate as almost linear fashion is observed. Mass loss of gunmetal reduces with the increase of stand-off distance. A dimensional analysis, erosion efficiency (η), and relationship between friction and erosion indicate the prominent correlation. The test results are designated using Taguchi’s and ANOVA concept. ratio indicates that there are 1.72% deviations that are estimated between predicted and experimental results. To elaborately analyze the results, ANN and GMDH methods are mentioned. After erosion process of tested composite, the damage propagation on surfaces is examined using SEM for the confirmation of possible nature of wear behavior. The elemental composition of eroded test samples at varying percentage of gunmetal is analyzed by EDX analysis.

Experimental analysis of aluminum alloy under solid particle erosion process

The erosion behaviors of aluminum alloy have been evaluated practically at different test conditions under ambient temperature. Irregular silica sand (SiO2) is used as an erodent within the range of 300–600 µm. The impact velocity within 30–50 m/s, impact angle 15–90°, and stand-off distance 15–25 mm considered as related parameters. The maximum level of erosion is obtained at impact angle 15° which indicates the ductile manner of the tested alloy. The higher the impact velocity, the higher the erosion rate as almost linear fashion is observed. Mass loss of aluminum alloy reduces with the increase of stand-off distance. A dimensional analysis, erosion efficiency (η) and relationship between friction and erosion indicate the prominent correlation. The test results are designated using Taguchi’s concept to ensure the minimization of observations for clarification of results in alternative process. ANOVA data analysis is considered to signify the interaction of tested parameters as well as identifying most influencing operating parameter. S/N ratio indicates that there are 2.92% deviations estimated between predicted and experimental results. To elaborately analyze the results, GMDH method is mentioned. After erosion process of the tested composite, the damage propagation on the surfaces is examined using SEM for confirming wear mechanisms. The elemental composition of eroded test samples at varying percentage of aluminum is analyzed by energy dispersive X-ray spectroscopy analysis.

Erosive wear characteristics of multi-fiber reinforced polyester under different operating conditions

Composite materials are used in a wide range of applications. The erosion properties of combination of glass, jute and carbon fiber-reinforced polyester were analyzed in this study. Randomly-shaped silica (SiO2) particles of various sizes (300-355μm, 355-500μm, and 500- 600μm) were selected as the erosive element. Impingement angles between 15-90°, impingement velocities between 30-50 m/sec, and stand-off distances of 15-25 mm at ambient temperature were selected. During experiment, the maximum erosion of the tested composite occurred at 60° impingement angle, indicating a semi-ductile nature of the test material. Erosion increased with impact velocity and decreased with stand-off distance. In a dimensional analysis, erosion efficiency (η) and the relationship between friction and erosion were established. Test results were evaluated using Taguchis concept to minimize the observations needed, and ANOVA was used to identify interactions between tested parameters and to identify the most significant parameters. The S/N ratio indicates that there is only percentage of deviation between the predicted and experimental results. In further, sophisticated analyses and GMDH methods were employed, and surface damage was examined using scanning electron microscopy (SEM) to examine the nature of the wear behaviour.

Erosion characteristics of Teflon under different operating conditions

Abstract The present study investigated the solid particle erosion characteristics of Teflon under different impingement angles (15–90°), impact velocities (30–50 m/s), erodent sizes (300–600 μm) and stand-off distances (15–25 mm) at ambient temperature. The Teflon showed ductile erosion behavior exhibited a peak erosion rate at a 30° impact angle. The design of experiments approach utilizing Taguchi’s orthogonal arrays was applied to test the specimens on a compressed air jet type erosion test rig. Erosion efficiency (η) values were 0.29–16.7%, which indicates micro-plugging, plastic deformation and micro-cutting action as dominating erosion mechanisms. The experimental results are closer to the theoretical model. An optimal parameter combination was determined, which leads to minimization of erosion rate. Analysis of variance (ANOVA) was performed on the measured data and signal-to-noise (S/N) ratios. A mathematical correlation, consistent with the experimental observations, is proposed as a predictive equation for estimation of erosion rate of tested material. The morphology of erodent surfaces was examined by using scanning electron microscopy (SEM). Possible erosion mechanisms are discussed.

Estimation of the friction coefficient in turning process of metals through model experiment

An in-procedure tribometer is analyzed to assess the friction during orthogonal turning process at cutting rates of up to 300 m/min to determine genuine cutting procedure conditions. The examined tribometer consists of a spring preloaded tungsten carbide with (5% to 8%) cobalt pin with the rounded tip mounted behind the bleeding edge and in contact with the naturally produced workpiece plane. The pin preload is fitted by feed power or force. A 3D-feed force measuring gadget in the obsession of the pin facilitates the assessment of the friction coefficient from tangential and typical strengths. Tests indicate considerably diverse results while reaching new and oxidized planes as well as diminishing friction coefficients as the cutting velocity increases. In general, greater graphite content decreases the friction coefficient and the temperature inclines in the wear pin. A uniform scattering of graphite particles in steel composites enhance their irritating resistance. Moreover, the wear rates for these amalgams are lower than those for similar combinations without graphite. Plane or surface equality is the key predictor of roughness. Plane inequality decreases as cutting speed increases and vice versa.

Friction and Wear of Non-Ferrous Materials Under Artificially Created Vibration for Machine Design

In this study, variations of friction and wear with the variation of the amplitude and frequency of normal vibrations were observed experimentally when mild steel pin slides on copper, aluminium and gunmetal using pin on disc test rig. The background of the study was to find the way of reduction of friction and wear under vertical vibration using artificially created external vibration mechanisms. The test parameters included the sliding speed (1 m/s), normal force (10 N), relative humidity (70%), amplitude (10-200 µm), and frequency (50-250 Hz). Results reveal that the friction coefficient decreases with increased in amplitude and frequency of vibration within the observed range. The reduction rate of friction coefficients and wear rate are different for different tested materials. Roughness affected the friction in conjunction with vibration. The results can be used in the selection of the most appropriate nonferrous material in mechanical and tribological applications.

Study of erosion characterization of carbon fiber reinforced composite material

Carbon fiber composite materials are widely used at different engineering and industrial applications there are good physical, mechanical, chemical properties and light weight. Erosion behavior of materials depends on various factors such as impact angle, particle velocity, particle size, particle shape, particle type, particle flux, temperature of the tested materials. Among these factors impact angle and particle velocity have been recognized as two parameters that noticeably influence the erosion rates of all tested materials. Irregular shaped sand (SiO2) particles of various sizes (200–300 µm, 400-500 µm, and 500-600 µm) were selected erosive element. Tested conditions such as impingement angles between 15 degree to 90 degree, impact velocities between 30-50 m/sec, and stand-off distances 15-25 mm at surrounding room temperature were maintained. The highest level of erosion of the tested composite is obtained at 60° impact angle, which signifies the semi-ductile behavior of this material. Erosion showed increasing trend with impact velocity and decreasing nature in relation to stand-off distance. Surface damage was analyzed using SEM to examine the nature of the erosive wear mechanism.Carbon fiber composite materials are widely used at different engineering and industrial applications there are good physical, mechanical, chemical properties and light weight. Erosion behavior of materials depends on various factors such as impact angle, particle velocity, particle size, particle shape, particle type, particle flux, temperature of the tested materials. Among these factors impact angle and particle velocity have been recognized as two parameters that noticeably influence the erosion rates of all tested materials. Irregular shaped sand (SiO2) particles of various sizes (200–300 µm, 400-500 µm, and 500-600 µm) were selected erosive element. Tested conditions such as impingement angles between 15 degree to 90 degree, impact velocities between 30-50 m/sec, and stand-off distances 15-25 mm at surrounding room temperature were maintained. The highest level of erosion of the tested composite is obtained at 60° impact angle, which signifies the semi-ductile behavior of this material. Erosion show...

Study of Erosion Performance and Characterization of Ebonite Reinforced With Carbon Fibers

Composite materials have many applications at different mechanisms in industry. The erosion characteristics of new combinations of ebonite reinforced with carbon fiber were analyzed in this study. Randomly-shaped sand (SiO2) particles of various sizes (300–355, 355–500, and 500–600 μm) were selected erosive element. Tested conditions such as impact angles between 15 and 90°, impact velocities between 30 and 50 m/s, and stand-off distances 15–25 mm at surrounding room temperature were maintained. The highest level of erosion of the tested composite was obtained at 60° impact angle, which signifies the semi-ductile behavior of this material. Erosion showed an increasing trend with impact velocity and decreasing nature in relation to stand-off distance. Surface damage was analyzed using SEM to examine the nature of the erosive wear mechanism.

Deposition rates on stainless steel substrates of different surface roughnesses under different operating conditions using thermal CVD

A series of experimental tests were carried out to observe the deposition rates on different stainless steel substrates of different surface roughnesses under different operating conditions using a hot filament thermal chemical vapour deposition (CVD) reactor. The test parameters include gas flow rate of methane, temperature of substrate and activation heaters, distance between activation heater and substrate, pressure and duration. There are significant effects of these parameters on deposition rate of different stainless steel materials. It was found that deposition rates strongly depend on different surface roughnesses of the stainless steel substrates under different tested conditions within the observed range. Tribological properties, especially friction and wear of these stainless steel materials sliding against SS 314 under different normal loads and sliding velocities are also investigated before and after deposition. The obtained results reveal that the values of friction and wear are lower after deposition than that of before deposition.