Chamfer Angle Research Articles

Influence of substrate edge chamfer geometric features on the edge effect of spin-coating film

Abstract The spin-coating method is a widely employed technique for thin film fabrication. However, edge effects can adversely affect the quality and utility of the films produced. This study investigates the influence of chamfered edges on the substrate during the spin-coating process on edge effects. Both experimental and simulation results indicate that smaller chamfer angles contribute to reducing the width of edge effects. Conversely, the width of the chamfer has a relatively minor impact on the extent of edge effects.

Numerical Simulation and Experimental Study of Carbon Fiber-Reinforced Polymer Single-Bar Extrusion Anchorage Structure.

The reliable anchorage of carbon fiber-reinforced polymer (CFRP) tendons is a critical issue influencing the stable bearing capacity of bridge cables. This study introduces a novel CFRP single-strand extrusion anchoring structure, where the strand is compressed at its end. By integrating this with internal cone filler wrapping, we create a CFRP multi-strand cable composite anchoring system. This innovative design not only minimizes the overall dimensions of the anchoring system but also significantly improves its anchoring efficiency coefficient. An axisymmetric model was developed using ANSYS finite element software. The radial stress distribution and anchorage efficiency coefficient in the anchorage zone of Φ7 CFRP bar and Φ13.6 extrusion die were analyzed with varying parameters, such as chamfering, outer diameter, and length of the extrusion sleeve, and were validated through static load anchorage tests. The results indicate that the highest anchoring efficiency is achieved when four extrusion sleeves with a chamfer angle of 5°, an outer diameter of Φ14.4, and a length of 15 mm are connected in series, reaching a coefficient of 61.04%. Furthermore, this study proposes an anchorage structure where multiple extrusion sleeves are connected in series and sequentially compressed to overcome the limitations of increasing anchorage length for enhancing the anchorage coefficient. The test results demonstrate that with equal total anchorage length, connecting four 15 mm extrusion sleeves in series enhances the anchorage efficiency coefficient by 24.98% compared to a single 60 mm extrusion sleeve structure.

Effect of Chamfered Turbulators on Performance of Solar Air Heater - Numerical Study

This paper presents a numerical analysis of the thermal performance improvement in a flat plate solar air heater equipped with chamfered turbulators attached below the absorber plate for evaluating performance for Reynolds numbers ranging from 3,000 to 21,000. According to the research, chamfered turbulators caused the flow to become highly turbulent. This flow behaviour with flow separation around the turbulators positively affects performance. This paper attempts to explain the complex flow behaviour found during the analysis. The turbulator diameter varies in 1 mm increments from 3 to 7 mm at a constant longitudinal pitch of 200 mm. The number of turbulator rows in the transverse direction is kept constant at three. The chamfer is represented by the flow attack angle, which can be 30°, 45°, or 60° facing the direction of flow and opposing the direction of flow. The results showed that a 7mm diameter turbulator with a 30° chamfer angle placed against the flow of air yielded a considerably more significant thermal enhancement factor of 1.15 over the spectrum of flow Reynolds number studied

Simulation of soil cutting blade wear

The results of a laboratory study of the wear patterns of blades of tillage parts are presented. To substantiate the model of soil-cutting blade wear in laboratory studies. Applied installation, providing rectilinear movement of the sample, one-time interaction of the blade with the particles of abrasive mass, and reproducing chip separation, inherent in most loamy soils. The dependence of the angle of inclination of the occipital chamfer to the bottom of the furrow, the width of the occipital chamfer and blade wear along the length of the sample from the cutting path, taken in studies for the main parameters of wear, were obtained. It was found that with increasing depth of cut, the intensity of wear increases, but when there are irregularities and undulations of the bottom of the furrow, it decreases due to the increase in the cutting path with lower loads due to the alternation of depressions and protrusions at the bottom of the furrow. With increasing hardness of the abrasive mass, the intensity of wear of the blade increases, at the same time the value of the stabilized angle of the occipital chamfer to the bottom of the furrow decreases, due to changes in the wear mechanism. With increasing cutting speed, the intensity of blade wear increases due to increased soil resistance forces and specifi c energy expended on its deformation and destruction. It was shown that the abrasive model of the soil corresponds to the real loamy soil for the study of wear of cutting elements. The expansion of the characteristics of the soil model peculiar to "nature" is due to the inclusion of additional components, in particular ceresin and vaseline, in the composition of the base "paraffin + quartz particles".

The Effect of Chamfer Angle Variations on the Quality of Friction Welding Results of AZ-31B Magnesium

Friction welding is one of the solid-state welding types. Friction welding is a joining process whose application melts the material itself by using the heat generated between the surfaces through a combination of rotational motion and the application of compressive loads. The use of magnesium alloys is widely used in various industrial fields, examples of magnesium alloy applications include coating materials from iron and steel as a means of protecting against corrosion. The use of AZ-31B series magnesium alloys has a high specific strength compared to other series such as AM. The purpose of this final project research is to determine the effect of the addition of chamfer angle on the tensile strength value and microstructure of AZ-31B magnesium friction welding results. From this research, the results obtained in tensile testing are that the addition of the chamfer angle to the surface of the weld specimen will increase the tensile strength value. The highest maximum stress value was obtained in the chamfer angle variation of 300 with an average of 228.525 MPa and the lowest maximum stress value was in the material that did not use the chamfer angle variation with an average of 105.722 MPa. Based on microstructure testing, it shows differences in ?- Mg and ?-Mg phase grains17 Al12 in each region, this is influenced by heat and also the melting generated from welding so that it changes its microstructure.

Исследование кинетики формообразования деталей сферического подшипника скольжения из коррозионно-стойких сталей, полученных объемной штамповкой пористых заготовок

Introduction. Spherical powder sliding bearings are widely used in various branches of mechanical engineering. Therefore, the development of a promising method of production of spherical sliding bearing parts from powders of corrosion-resistant steels with specified properties is an urgent task. Purpose of work: is to study the kinetics of forming during cold die forging of spherical sliding bearing parts from stainless steel powder blanks, and to assess the effect of the chemical composition of lubricants and the design of the pressing tool on the structure and properties of the bearing outer ring. Materials from sprayed powders of stainless chromium-nickel steels obtained by cold die forging of sintered blanks coated with lubricants are studied in the work. The following research methods were used: mechanical tensile testing, metallographic studies and cold die forging process simulation. Results and its discussion. It is revealed that the resistance and work of deformation, as well as the kinetics of forming of the outer ring of the spherical sliding bearing are influenced by chemical composition of powders and lubricants, microstructure and mechanical properties of the blank material, configurations of the end surfaces of punches. The top and bottom edges of the outer bearing are most intensively sealed when the punch faces are made with a chamfer angle of 30–40 degrees. With an increase in the relative strain degree by height up to 0.30–0.35 its residual porosity amounted to 0.5–2.0 %. The features of definition of strain state and calculation of strain energy in the implementation of the offered method and the choice of technological parameters of the cold die forging process of sliding bearings parts are shown. A simple method for calculating and experimentally determining the coefficient of contact friction in the process of cold die forging of porous stainless steel blanks is developed, which allows to establish the effect of lubricant composition on the strain resistance at different values of the degree of radial deformation and to develop optimal methods of cold die forging of porous blanks in the production of parts of different complexity.

Research on Cogging Torque Reduction of Direct-Drive Type Dual-Rotor Radial Flux Permanent Magnet Synchronous Motor for Electric Propulsion Aircraft

The direct-drive type high-torque-density motor is one of the most promising solutions of electric propulsion for aircraft. The cogging torque of the direct-drive motor causes torque ripple, vibration, and noise, which seriously affect the stability and reliability of the electric propulsion system for aircraft. In this paper, a novel direct-drive type high-torque-density dual-rotor radial flux permanent magnet synchronous motor (DRPMSM) is proposed, and its cogging torque is weakened by permanent magnet shape design and pole-arc coefficient combination. An eccentric and chamfered permanent magnet shape is proposed, and the influence of eccentric distance and chamfer angle on cogging torque is clarified. Through the pole-arc coefficient combination design of the inner and outer rotors of the DRPMSM, the cogging torques of the inner and outer rotor are phase reversed, thus further reducing the total cogging torque of the DRPMSM. By employing the response surface method, a mathematical model is established for the cogging torque of the DRPMSM in relation to the pole-arc coefficients, chamfer angle, and eccentric distance of the permanent magnets. The parameters that minimize the cogging torque of the DRPMSM are obtained using a genetic algorithm. A prototype is manufactured according to the optimized parameters, and experimental results validate the correctness of the theoretical analysis and the effectiveness of the optimization design method.

Numerical simulation and tool parameters optimization of aluminum alloy transmission intermediate shell

Due to its challenging manufacturing and intricate morphology, the aluminum alloy transmission intermediate shell used in vehicle transmission has been the focus of many academic studies. In this study, the three-dimensional cutting model is condensed to a two-dimensional cutting model and utilized to simulate the finishing process of an aluminum alloy workpiece using the finite element modeling program DEFORM-3D. Through orthogonal testing and range analysis, the impact of integral end mill side edge parameters on cutting performance was investigated. It is determined that tool chamfering has a greater impact on cutting performance than tool rake and relief angles, that chamfering width has the most impact on cutting force, and that chamfering angle has the greatest impact on cutting temperature. The workpiece's surface roughness is tested during a cutting experiment, and an analysis of the data reveals that the finite element simulation model is accurate and the orthogonal test method is reasonable. The tool chamfer has a greater impact on roughness than the tool rake angle and relief angle. The tool settings are further optimized using the firefly method. By examining the data, it is determined that the prediction model is correct and the optimization model is reasonable. The cutting efficiency is higher and the surface quality is better when the chamfer width is 0.17 mm and the chamfer angle is 7.3° or 18.3°. Therefore, optimizing the side edge parameters of the integral end mill during the finishing process of a thin-walled aluminum alloy shell has practical technical value.

Influence of geometry variations during pyrometric temperature measurement in laser material processing

Pyrometric temperature measurements, essential for quality assurance in laser processing, are challenged by the angular dependence of emissivity with varying local geometries. Therefore, this contribution presents investigations on the influence of geometry variations on pyrometric temperature measurements for geometry variations at different measurement positions and within the measurement spot.For this, laser-heated copper samples with chamfers are used and the measurement spot of the pyrometer is moved over the edge of the chamfer to cover different geometric areas. Three chamfer angles and three measurement spot sizes were examined. In addition, a theoretical calculation has been performed and compared with the experimental results. The study shows the significant influence of geometry variations on the pyrometric temperature measurement.

Optimizing rock breaking performance: The influence of chamfer on polycrystalline diamond compact (PDC) cutters

Research on the rock-breaking performance of the Polycrystalline Diamond Compact (PDC) cutter has primarily focused on sharp cutters, often overlooking the influence of chamfer. Notably, the design of chamfer parameters has been largely unreported. In this study, we established a theoretical model of cutting force that takes chamfer into account. We analysed the primary and secondary relationships of four factors – back rake angle, depth of cut, chamfer angle, and chamfer length – on the force of the PDC cutter. This was done through a pseudo-level orthogonal level test. A numerical simulation, based on the Smooth Particle Hydrodynamic (SPH) method, was conducted to analyse the rock-breaking force and stress distribution characteristics of PDC cutters with different chamfer angles. Combined with a drop hammer impact test, we provided an optimized design of chamfer parameters. Our findings revealed that while the chamfer had a relatively minor influence on the force of the PDC cutter, it contributed to the optimal distribution of stress on the PDC cutter. This effectively protected the cutting edge and prevented early cracks and spalls of the cutter. When the chamfer angle was less than or equal to the back rake angle, the resultant force of the PDC cutter increased with the increase of the chamfer angle. However, when the chamfer angle was greater than the back rake angle, the resultant force of the PDC cutter first increased and then slightly decreased with the increase of the chamfer angle. Additionally, the resultant force of the PDC cutter increased approximately linearly with the increase of chamfer length. When the chamfer angle of the PDC cutter was between 30° and 45°, the fluctuation of the cutting force was relatively smooth, the rock-breaking process was stable, and the cutter’s impact resistance energy was relatively higher. These findings will provide valuable guidelines for the design of chamfered PDC cutters.

Experimental study on the dynamics of a spark bubble near the top of a cylinder and associated annular secondary cavitation bubbles

This paper presents an experimental study focused on the annular secondary cavitation caused by the interaction between a high-voltage spark bubble and a cylinder. A 2000 V high-voltage underwater electric discharge was used to create the bubble, which reached a maximum diameter of approximately 31 mm. High-speed photography was employed to capture the behavior of the spark bubble and the induced secondary cavitation bubbles. The formation and evolution of the annular secondary cavitation bubbles near the cylinder's edge were captured and analyzed. The study classified the morphology of the annular secondary cavitation bubbles into three different types based on various bubble distances and cylinder diameters. Notably, unique bubble morphologies, such as the terraced bubble shape, were identified, resulting from the coupling between the spark bubble, the annular secondary cavitation bubble, and the cylinder. The interaction between the annular secondary cavitation bubble and the spark bubble, including coalescence, and the resulting effects on bubble shape and period were investigated. The changes of secondary cavitation bubbles are compared when the cylinder has different chamfer angles. Moreover, the study examined the dynamic characteristics of the bubbles, including their shape evolution, jetting behavior, period length, and pressure pulses upon collapse, at various distances from the top-surface of cylinders with different diameters. The experiment also introduced flow visualization with dye into spark bubble experiments for the first time to trace the vortex around the annular secondary bubble. Additionally, the transparency of bubbles in the images was improved through multi-source lighting techniques.

The Effect of Variation of Bar Surface Chamfer Angle on Rotary Friction Welding Connections

This study aims to determine the effect of chamfer angle variations on flash, welding time, interface and hardness values at welded joints of similar materials. The method was used, with parameters of the rotational speed of 4.335 rpm, friction pressure of 0.5 MPa, forging pressure of 0.7 MPa, forging time of 10 seconds and chamfer angle variations of 0°, 15°, 30°, 45°. Then, the specimen result was tested using the projector profile, Non-Destructive Test (NDT), macro-observation, and Vicker test. The result showed that the greater the chamfer angle variation on the given bar surface, the smaller the size of the resulting flash. The smallest flash dimension was produced at a chamfer angle variation of 45°, with an average flash height of 1.03 mm, successfully reducing the flash height by 62% from variations without chamfer angles. Moreover, an average flash width of 0.26 mm reduced the flash width by 77% of the variation without a chamfer angle. Therefore, the greater the variation of the chamfer angle, the smaller the flash size and the more significant the variation of the chamfer angle, the longer the welding time. In the interface area, chamfer angle variations do not affect cracks and voids. The chamfer angle affects the average hardness value, where the more significant the chamfer angle, the more the hardness value is increased.

Enhanced heat transfer and flow topology of hydrogen regenerative-cooling channels with novel X-shape ribs

One of the essential issues for spacecraft is maintaining the combustion chamber wall from exceeding acceptable temperatures. The cooling channels' thermal resistance and flow topology can be augmented by adding ribs to the heated surface. The present work proposed a Novel X-shape rib to enhance the thermal efficiency of hydrogen regenerative-cooling channels. The numerical investigation was carried out for the cooling system with rectangular and trapezoidal X-shape ribs at various attack angles (30°,45°, and 60°). The investigation findings demonstrated that both X-shape rib constructions optimized the cooling system's thermal efficiency. Since the trapezoidal X-shape ribs' chamfering angle reduces the resistance to coolant flow, the pressure loss of these ribs is less than rectangular ribs. Additionally, the heat transfer rate is maximum for 30° X-shape ribs, decreasing gradually with the increase of the X-shape rib's attack angle. Furthermore, compared to a smooth channel, the rectangular 30° X-shape ribs enhance the thermal efficiency by 44% while reducing the wall temperature by 24%.

Simulation of Work Hardening in Machining Inconel 718 with Multiscale Grain Size.

Machining nickel-based alloys always exhibits significant work-hardening behavior, which may help to improve the part quality by building a hardened layer on the surface, while also causing severe tool wear during machining. Hence, modeling the work-hardening phenomenon plays a critical role in the evaluation of tool wear and part quality. This paper aims to propose a numerical model to estimate the work-hardening layer for a deeper understanding of this behavior, employing both recrystallization-based and dislocation-based models to cover workpieces with multiscale grain sizes. Different user routines are implemented in the finite element method to simulate the increase in hardness in the deformed area due to recrystallization or changes in the dislocation density. The validation of the proposed model is performed with both literature and experimental data for Inconel 718 with small or large grain sizes. It is found that the recrystallization-based model is more suitable for predicting the work-hardening behavior of small-grain-size Inconel 718 and the dislocation-based model is better for that of large-grain-size Inconel 718. Further, as an important type of cutting tool in machining Inconel 718, the chamfered tools with different edge geometries are employed in the simulations of machining-induced work hardening. The results illustrate that the uncut chip thickness and chamfer angle have a significant influence on the work-hardening behavior.

Influence of rectangular substrate chamfer on edge bead effect of a spin-coated thin film

Spin coating is a common method for fabricating thin films. The edge bead effect is a major contributor to thin film non-uniformities. This study investigates the influence of chamfer angles and widths of a rectangular substrate on the edge bead formation mechanism in spin-coated films. Through the use of volume-of-fluid simulations and experiments, it was determined that the chamfer angle had a significant impact on the edge bead effect, while the chamfer width was not found to be a major factor. The use of a synchronous chamber in spin coating was found to negatively affect film planarization by restricting solvent evaporation and elevating its concentration, leading to a decreased film thickness. Additionally, the study concluded that the edge effect is not impacted by the Bernoulli effect or liquid accumulation along the edge if the average film thickness is below 1500 nm. The main reason for reducing the height of the edge bead was determined to be liquid fusion at the edge of the substrate, which only occurred when the chamfer width was close to the film thickness.

A hybrid microchannel heat sink with ultra-low pressure drop for hotspot thermal management

Hotspot with several orders of magnitude heat flux higher than the background areas has become a prominent issue in the thermal management of advanced electronics. In this study, a novel microchannel heat sink with ultra-low power consumption has been introduced for chip-level hotspot thermal management. The proposed IM-HM heat sink incorporates rectangular microchannels for the background zone and pin-fins for the hotspot region, configured with an upper inlet and two side outlets. Using maximum temperature, pressure drop, and temperature uniformity as key metrics, a comprehensive numerical analysis of the IM-HM heat sink at different Reynolds number were conducted based on computational fluid dynamics. Our results demonstrate that the IM-HM heat sink enhances local heat transfer capacity and exhibits better temperature uniformity compared to the traditional rectangular microchannel heat sinks. Moreover, incorporating entry chamfer and augmenting the microchannel height have been found to effectively mitigate pressure drop in microfluidic systems. Specifically, simulation results indicate that the pressure drop in the microchannel can be reduced by 63.4 and 72.3% by increasing the inlet chamfer angle and microchannel height to 500 and 1500, respectively. Notably, the optimized IM-HM heat sink yields over 98.4% savings in pumping power to achieve consistent maximum temperatures compared to traditional rectangular microchannel heat sinks, while also exhibiting smaller temperature gradient.

Finite Element Analysis of the Influence of Chamfer Hub Geometry on the Stress Concentrations of Shrink Fits

The theoretical expressions commonly used in the design of interference fits do not take into account the huge stress concentrations located at the edges of the hub. This underestimation of the real stress state can induce the incorrect performance of the shaft–hub assembly. Among the different methods to address this problem is the use of chamfer hubs, which are used for reducing such stress concentrations. In this paper, an analysis, performed via finite element method, of the influence of the geometric parameters of a shrink fit with chamfer hubs was carried out with the aim of determining the optimal dimensions for the design of this type of mechanical assembly. To achieve this goal, different chamfer hub geometries were considered: (i) full–chamfer hubs defined by the chamfer angle and (ii) partial–chamfer hubs defined by the chamfer angle and the chamfer height. According to the obtained results, stress concentrations can be reduced by using a full–chamfer hub with chamfer angles within the range 13°–15° depending on the hub thickness. In addition, similar results can be obtained by using partial–chamfer hubs with a chamfer height of half of the hub thickness and chamfer angles within the range 13°–15°. By using these design recommendations, the theoretical equations can be used without underestimating the real stress state.

The evaluation on performance of narrow- gap welding thick steel plates under the influence of main welding parameters

This work presents the experimental results of narrow gap butt welding of steel plates with large thickness by using the Metal Active Gas (MAG) welding method.The typical defects are accompanied with this process such as the infusion in the side wall and the porosity due to the narrow gap which affect on the melting process. Thus, some publications noted the results of welding for the thickness up to 20−30 mm and the chamfer angle about 30° using GMAW/MIG, GTAW/TIG, SMAW and new development such as laser – arc hybrid, laser multi- pass technique, super -TIG welding etc. But the production requires the solution to save the costs by the reduction of time, labour and investment keeping the standard quality. That is the aim of this study. In order to improve the quality of weld joint and increase the productivity of the process, is it suggested to develop the innovative welding process, in which the welding voltage – Uw, the translational velocity of the tip – Vt, and rotational velocity of the tip – Vr, are changing. This helped to increase the thickness of steel plates up to 50 mm and the chamfer angle decreased at 15°, providing the satisfied quality of the weld. The micrography study serve as the preliminary proof of this hypothesis.
 The microstructures in 4 regions, such as the weld center zone, heat-affected zone (HAZ), parent metal region, and the boundary between the weld metal and the HAZ were examined. The microstructures of 13 positions from different experiments are investigated using the optical microscope (Axiovert 25).These experiments covered all specific points (node) locating accordingly to three layers from bottom to top of the weld joint . The findings proved the welding quality is similar in case of narrow gap but the chamfer angle is twice lower and the thickness is increased. The result of the study enhances the productivity due to saving the labour cost and the welding materials. It is recommended to consider the effect of other factors (such as cooling conditions, dwell time when the arc approaching the side walls) to optimize the weld quality. There is the huge volume of the heavy steel constructions with the thick steel construction and specific narrow gap in industry. The results of this study with the optimization and more deeper evaluation the influence of main parameters of welding process to eliminate the typical defects will be the valuable reco mmendation for the managers and engineers in the production of metallic constructions

Study the effect of the tooth chamfer angle on the dog clutch shiftability

This paper studies the shiftability of the face dog clutch with chamfered teeth. The effect of the chamfer angle on the shiftability map and the probability are studied. In contrast to previous studies, a generalized mathematical model is developed based on the shiftability condition. The analysis considered two sets of cases: the overlap distance cases, and the chamfer side cases. The overlap distance cases locate the successful engagement position. The chamfer side cases investigate the effect of the system geometry and consider two cases. The results show that the chamfer angle has a negative effect on the dog clutch shiftability. Some geometric parameters show a different effect on the engagement probability for the rectangular tooth and chamfered tooth cases, and this behaviour is also analysed.

On the Lubricity and Comparative Life Cycle of Biobased Synthetic and Mineral Oil Emulsions in Machining Titanium Ti-6Al-4V at Low Cutting Speed

The paper discusses an instrumented tapping test method using a CNC machine tool to compare the lubricity of MWFs by cutting threads in a Ti-6Al-4V alloy at low speed. The method uses a spiral flute tap size typical of industrial practice. A soft synchronous tap holder and spindle mounted dynamometer were incorporated on the machine to measure torque and thrust force. The tapping test method was demonstrated on three groups of MWFs that were commercially available and classified by ASTM E2523-13:2018. The method developed stable results free of chip clogging in tool flutes which could otherwise mask their comparative lubricity. The fully synthetic (FS) group displayed the best lubricity and within this group the FS from renewables (FS-bio) was the best overall. The method was shown to be effective in mitigating biasing effects on lubricity performance due to the generous tool chamfer angle tolerance and was practical and economical to implement. The significance of the results is discussed enabling an understanding of friction effects in tapping using a soft synchronous tap holder. A life cycle assessment of each MWF group found total Greenhouse Gas emitted from the FS group was 17% of the hydrocarbon group whilst FS-bio emitted just 7%.