Increase Of Spindle Speed Research Articles

Experimental Study of a Novel Ultrasonic Vibration-Assisted Structure for Radial Milling

A novel ultrasonic vibration-assisted structure for radial milling is proposed, and the ultrasonic vibration-assisted radial milling (UVARM) is further studied in terms of theoretical model and milling experiment. The motion and feed characteristics of UVARM are also analyzed. A special fixture is designed to construct the experimental platform of UVARM, in which the vibration is applied to the workpiece along the radial direction. The preliminary results show that with the increase of spindle speed, the milling force in both conventional cutting (CC) and UVARM experiments tends to increase. In addition, when the feed per tooth increased, the milling force increased. With the involvement of ultrasonic vibration, the milling force is significantly reduced, with the maximum reduction reaching 20%. The comprehensive analysis showed that there was a decrease of about 10% to 25% in the ultrasonic case compared with the conventional method. It is also found that UVARM can inhibit the production of a built-up edge. With the ultrasonic vibration, the burrs on the processed surface are also reduced, and the grooves left by tool traces are shallower. Compared with conventional milling, the roughness value of the machined surface obtained by UVARM is reduced by 10% to 32%. The experimental results also show that UVARM can effectively improve the dimensional accuracy of the workpiece.

Effect of Spindle Speed and Feed Per Tooth in Feed Rate Perspective on Inconel HX Cutting Force

Reducing feed rate during end-milling of nickel-based superalloys for low-cutting force has always been a common approach. This is due to these alloys having superior properties, making them widely regarded as difficult-to-machine materials. As feed rate is tied to spindle speed and feed per tooth, it is crucial to comprehend whether spindle speed, feed per tooth or the interaction between spindle speed and feed per tooth has a significant factor on cutting force reduction when increasing the feed rate. Accordingly, this manuscript presents an effect of spindle speed and feed per tooth in feed rate perspective on Inconel HX cutting force. Half-immersion down-milling and full-immersion down-milling was conducted experimentally using solid ceramic end-mill cutter. The results indicate that cutting force decreases and then increases after further increase in spindle speed, while cutting force increases with an increase in feed per tooth. Optimum spindle speed and optimum feed per tooth for low-cutting force were 21,400 rpm and 0.013 mm/tooth. Furthermore, feed per tooth was the significant factor which influenced the cutting force, whereas spindle speed, and the interaction between spindle speed and feed per tooth were not significant.

Construction of Milling Force Model of Cycloid Gear

The change of the milling force during the milling process will directly affect the machining accuracy of the cycloid gear. In this article, the milling force prediction model of the cycloidal gear is used to predict the milling force of the cycloid gear. The results show that when the spindle speed increases, the milling force gradually decreases; the milling force is also closely related to the feed speed, axis milling depth and radial milling width. With the increase of axial milling depth and radial milling width, the milling force gradually increases, but the magnitude of the increase is different.

Study the effect of anti-vibration edge length on process stability of milling thin-walled Ti-6Al-4V alloy

Owing to limited rigidity and wall thickness, the machining of thin-walled components leads to chatter, poor surface quality, and low productivity. It is well-acknowledged that end-mill geometry and cutting conditions have a significant influence on the process stability of thin-walled parts. In order to reduce the milling chatter, an anti-vibration milling tool with an anti-vibration edge (60, 90, 120μm) on the flank face is proposed based on the analysis of the process damping effect. The dynamic modeling, numerical computation, and confirmatory experimental analysis are carried out to investigate the effect of anti-vibration edge length on the milling stability of thin-walled titanium-alloy components. The computation results have shown a stable and gradual increase in stable depth-of-cut with the increase of anti-vibration edge length at constant spindle speed. The ultimate stable axial depth increases with the increase of the anti-vibration edge. Besides, the increase of spindle speed reduced the interference between the flank surface of the milling tool and the workpiece due to the decrease of curvature of the vibration mark on the workpiece surface. At higher cutting speed, the relationship between the stability axial depth and anti-vibration edge length reduced. The comparison of computational and experimental results indicate that the anti-vibration edge improved the process damping effect at low cutting speeds, and 120μm anti-vibration edge is optimum to manufacture the flank face of the tools.

Numerical Simulation and Experimental Study on the Drilling Process of 7075-t6 Aerospace Aluminum Alloy.

A finite element model for setting drilling conditions is established. The effect of feed speed and spindle speed on the drilling process was studied. In the test phase, drilling tests were conducted using three different feed speeds (60, 100, and 140 mm/min) and three different spindle speeds (800, 1000, and 1200 rpm). The correctness of the finite element model was verified by comparing the experimental and numerical simulation data. The results show that the axial force and torque increase significantly with the increase of feed speed, while the axial force and torque increase less as the spindle speed increases. The numerical simulation results show that the temperature of the cutting edge increases as the feed speed increases. Increasing the rotating speed increases the formation of chip curl. When the working conditions are high rotating speed and low feed, the tool wear is reduced, and the machining quality is better. The numerical simulation results obtained for the chip forming effect are similar to the experimental data. In addition, the simulation results show the generation of burrs. A comparison of the finite element simulation and experimental data leads to an in-depth understanding of the drilling process and ability to optimize subsequent drilling parameters, which provide reliable process parameters and technical guarantees for the successful implementation of drilling technology for space suspended ball structures.

Effect of machining parameters on cutting force during dry milling of 2205 DSS and 2507 SDSS materials

Duplex Stainless Steels (DSS) contain high chromium content and hence DSS are considered as difficult to machine material due to their exceptional strength and other physical properties. DSS are extensively used in food industries, petrochemical, Transport, paper making industries, pollution control equipments, sea water processing. In this study, the effect of machining parameters on cutting force was evaluated during CNC dry milling of 2205 Duplex Stainless Steel (2205 DSS) and 2507 Super Duplex Stainless Steel (2507 SDSS). Experiments were conducted by varying feed rate and spindle speed. Results exhibited a decrease in cutting force with a rise in spindle speed until 4200 rpm and beyond that it increased with the increase in spindle speed for both materials. When feed rate was increased, cutting force values increased for both 2205 DSS and 2507 SDSS grades. Higher cutting force values were recorded while machining 2507 SDSS compared to 2205 DSS under same cutting conditions. This is mainly due to the presence of high percentage of chromium content in 2507 SDSS material. From the analysis, it was noticed that spindle speed and feed rate have greater effect on cutting force during CNC dry milling operation.

The impact of process parameters on surface roughness and bushing in friction drilling

Friction drilling is considered a non-traditional hole making method in which the workpiece is penetrated by a conical rotating instrument and a bush is formed without producing chips in a single cycle. In the present work, using a CNC milling machine, the friction drilling process was carried out on Be-Cu C17200 plate material. The process parameters such as spindle speed and feed rate were performed over three levels of workpiece material thickness. Surface roughness, bush length, and the thrust force of the drilled holes were analysed following drilling. For optimal surface roughness and bush formation, it is noted that spindle speed and feed rate play a significant role in friction drilling. Higher feed rate and thrust force have a direct effect on greater roughness of the surface and increased bush length. Better bushing and surface roughness are given by an increase in spindle speed.

Simulation Analysis of Aviation Aluminum Alloy Reaming Processes by Using PCD Reamer

Cutting force and cutting temperature are two important parameters in the cutting processes. In this paper, AdvantEdge finite element analysis software was used to simulate and analyze the reaming process of aviation aluminum alloy 7050 by using PCD reamer. The cutting simulation model was established to investigate the effect of spindle speed, feed per tooth on thrust force and cutting temperature. Simulation results showed that the cutting force increased with the increase of feed per tooth at different spindle speeds. And in the case of different feed per tooth, the cutting force decreased slightly as the spindle speed increase. Besides, from the cutting temperature distributed in the reamer, the cutting temperature near the tip of the tool in the reaming process was highest, the cutting temperature increased with the increase of both spindle speed and feed per tooth.

Thermo-mechanical coupling effect on surface residual stress during ultrasonic vibration-assisted forming grinding gear

Abstract Gears are important motion and power transmission components and enhancing their machining accuracy and performance. In this work, a novel processing of ultrasonic vibration-assisted forming grinding gear (UVAFGG) is proposed, which involves the superimposition of ultrasonic vibration on the gear, and the thermo-mechanical coupling effect on surface residual stress is explored as well. Firstly, based on the local contact geometry relationship for forming grinding, the three-dimensional (3D) distribution model of the heat flux density along the tooth profile is established. In addition, the mathematical relationship models between the grinding force, grinding heat, residual stress, and grinding parameters are also given. Then, the effect of grinding parameters such as spindle speed and ultrasonic amplitude for the characteristics of residual compressive stress accumulation is obtained by comparing the single factor experimental and finite element simulation results. It is found that under the action of ultrasonic vibration, the grinding heat and grinding force reduce by 38.7% and 40.5 % and 40.5 %, respectively. The surface residual compressive stress gradually decreases with the increase in spindle speed, while with the increase in ultrasonic amplitude, it increases first and then decrease. Comparing with the conventional grinding gear (CGG), the average rate of increase of the surface residual compressive stress under the both parameters is 17.8 %–31.3 % and 20 % respectively. Meanwhile, the residual compressive stress along involute shows a negative correlation with the increase in the rolling angle. At the same time, the experimental and simulation results agree well with the theoretical model. In conclusion, the results of this study provide a novel process technology for gear machining, and a reference for the investigation on residual stress during UVAFGG.

Optimization of machining process parameters in Al 7175 metal matrix composites using Taguchi method

Aluminum-based metal matrix composites (MMC) have been used in various applications in the aerospace and automotive industries. Accomplishing a uniform circulation of support inside the framework is one such challenge, which influences straightforwardly on the properties and nature of composites. MMC is one of the authentic sources to satisfy the demand for engineering materials such as hardness, toughness, high tensile strength, low density, and good wear resistance. In this research work, Al 7175 metal matrix composites reinforced with 25% weight fraction of Sic and 4% weight fraction of graphite were synthesized through stir casting. Experiments were carried out based on L9 standard orthogonal array design for turning operation on Al 7175 using a tungsten carbide tool with three input process parameters, namely cutting speed, feed and depth of cut. The effect of input parameters on performance characteristics such as the material removal rate (MRR) and surface roughness (Ra) was studied. The signal to noise ratio was used to study the performance characteristics in turning operation. Results revealed that Ra reduced either on increasing spindle speed or by reducing feed, but depth of cut was not influential on Ra. MRR increased with increasing any of the three input parameters.

Nampt-mediated spindle sizing secures a post-anaphase increase in spindle speed required for extreme asymmetry

Meiotic divisions in oocytes are extremely asymmetric and require pre- and post-anaphase-onset phases of spindle migration. The latter induces membrane protrusion that is moulded around the spindle thereby reducing cytoplasmic loss. Here, we find that depleting the NAD biosynthetic enzyme, nicotinamide phosphoribosyl-transferase (Nampt), in mouse oocytes results in markedly longer spindles and compromises asymmetry. By analysing spindle speed in live oocytes, we identify a striking and transient acceleration after anaphase-onset that is severely blunted following Nampt-depletion. Slow-moving midzones of elongated spindles induce cortical furrowing deep within the oocyte before protrusions can form, altogether resulting in larger oocyte fragments being cleaved off. Additionally, we find that Nampt-depletion lowers NAD and ATP levels and that reducing NAD using small molecule Nampt inhibitors also compromises asymmetry. These data show that rapid midzone displacement is critical for extreme asymmetry by delaying furrowing to enable protrusions to form and link metabolic status to asymmetric division.

The Effect of Spindle Speed and Feed Rate on Hole Diameter of High-Speed Micro-Drilling for Micro-Screen Manufacture

The micro-drill is one of the manufacturing processes that is developing, especially in the electronics, aerospace, pharmaceutical, and automotive industries. This paper describes the results of the high-speed microdrill process in stainless steel. The drilling process is used to make the micro screen. The cutting tool material is tungsten carbide with a diameter of 0.2 mm. Drilling holes arranged in a honeycomb configuration. The machining parameters used are spindle speed of 20,000 rpm, 22,000 rpm, 24,000 rpm, and feed rate of 1 mm/min, 1.5 mm/min, 2 mm/min. Micro-drilling holes are visually analyzed using a Scanning Electron Microscope (SEM) to measure the accuracy of the hole dimensions. The results of the machining process found that the most significant deviation of the hole dimension size with a value of 0.276 mm occurred at a spindle speed of 20,000 rpm with a feed of 1 mm/min. While the deviation of the smallest hole size with a value of 0.2019 mm occurred at a spindle speed of 24,000 rpm with a feed of 2 mm/min, these results conclude that the accuracy of the hole dimensions will increase in proportion to the increase in spindle speed and feeding.

Study of Machining Parameter Optimization in Drilling of Magnesium Based Hybrid Composites Reinforced with SiC/CNT

Recently, researchers and engineers have been interested in the development of hybrid metal matrix composites (HMMCs) for the applications of automotive and aerospace industries owing to their superior properties due to the usage a wide range of material combinations in its manufacturing. The present study focuses on the machining of magnesium based hybrid composites reinforced with CNT (1vol.%) and SiC (2vol.%).The influence of machining parameters such as spindle speed, feed rate, drill diameter and point angle on burr formation and surface roughness on drilling the composites were investigated using Taguchi method. The drilling parameters were optimized by using ANOVA experimental design and also find out the percentage of contribution of each factor. Based on the results, the most influential factor for the burr thickness was spindle speed and point angle. While spindle speed and feed rate were the influencing factors for surface roughness. The analysis revealed that burr height, burr thickness, and surface roughness decreases significantly with an increase in spindle speed.

Experiment research on cavitation in high-speed milling with internal cooling

As the demand for difficult-to-cut materials (such as titanium alloys, nickel-based alloys, and stainless steels) continues to increase, internally cooled cutting is receiving increasing attention and research due to lowering the temperature of the cutting zone and improving the quality of the machined surface. With the increase of spindle speed, cavitation problem that plagues the development of high-speed fluid machinery may also cause cavitation damage to internally cooled cutting tools. This paper aims to study cavitation in the process of high-speed milling with internal cooling. A cavitation experiment platform for high-speed milling with internal cooling was established. A cavitation experiment was performed on the platform during high-speed milling with internal cooling. In order to facilitate the observation of cavitation during high-speed milling with internal cooling, Al 6063 and C45 were used as the materials of the workpiece and the milling tool, respectively. The experimental results reveal that after the experiment, fish scale cavity pits and cavitation pinholes were formed on the flank face and some machined surfaces of the workpiece. At the same time, the mechanism of cavitation damage was also preliminarily analyzed. This study is beneficial for exploring the cavitation mechanism in future high-speed internally cooled cutting and guiding the rational use of internally cooled cutting.

Determination of Milling Performance of Jute and Flax Fiber Reinforced Composites

ABSTRACT The usage area of natural fiber reinforced composite materials has been increasing day by day, due to their attaining to not only ecological benefits but also high mechanical properties with their low weight. After the fabrication of natural fiber reinforced composites, they need to be subjected to secondary processes such as milling, drilling and turning processes according to their field of use. In this study, it was aimed to determine milling performance of JFRP and FFRP composites, which are obtained from natural fibers. Experiments were carried out at the different processing parameters. The effects of these parameters on cutting force, vibration amplitude, delamination factor, and surface roughness were investigated. Vibration amplitude and delamination factor increased, and cutting force and surface roughness decreased with increasing spindle speed. Cutting force, vibration amplitude, delamination factor and surface roughness increased with increasing feed rate. The most appropriate values for cutting force, delamination factor and surface roughness were obtained in experiments where WC end mill was used. However, in vibration amplitude, the lowest values were HSS end mill. Delamination factors and surface roughness in FFRP composites were higher than those of JFRP composites. Cutting forces of FFRP composites were lower than those of JFRP composites.

Experimental investigations on cutting force and temperature in milling process of copper foam with high porosity

To protect pore structures of metal foam in the machining process, a new milling method was proposed that different filling materials were used for solidification of pore structure. In this way, the milling process was performed using the copper foams with three different types of filling materials (paraffin, rosin, and mixture of hydrogenated rosin and sodium stearate with a mass ratio of 4:1). During milling process of copper foam, the cutting forces and cutting temperatures were measured and analyzed. The surface morphology of copper foam was observed according to the SEM results. Moreover, the conformal rate, which was considered an index to estimate the quality of milling process, was calculated using pore size statistics. Our results show that with the increased spindle speed and feed rate, the conformal rate of pore structure was firstly increased and then decreased. With the increase of feed rate, the cutting temperature was slightly decreased. When the spindle speed was increased, the cutting temperature was increased, while the highest cutting temperature was much lower than the melting temperature of the filling materials. Better conformal performance and high conformal rate were obtained with the hydrogenated rosin and sodium stearate at a ratio of 4:1, at a spindle speed of 300 r/min and a feed rate of 160 mm/min. When the optimized processing parameters were adapted to milling the copper foam with filling material, the conformal rate can reach 96.4%. Correspondingly, the highest cutting temperature and the maximum cutting force perpendicular to the feeding direction and along the feeding direction were 37.4 °C, 44.91 N, and 24.60 N, respectively.

A Study on the Influence of Milling Parameters on the Properties of TC18 Titanium Alloy

Based on the orthogonal experimental design, the effect mechanism of different processing parameters on the surface microhardness and metal microstructure of TC18 titanium is studied. Meanwhile, the variation law of milling force and surface roughness of TC18 titanium alloy during high-speed milling is obtained. The results show that the milling depth has the greatest influence on the milling force under down-milling. Meanwhile, the milling depth and spindle speed have the greatest influence on the milling force in up-milling, which with the increase of milling depth and with the increase of spindle speed and downward trend. The greatest influence of surface roughness is the milling depth, and the surface roughness decreases with the increasing of milling depth. After milling complete, the surface hardness of TC18 titanium alloy work piece decreases. With the surface depth increases to 0.01 mm, the hardness is slightly higher than the matrix hardness. The microstructure of TC18 matrix is mainly β phase by observing the metallographic structure. The equiaxed α phase grows after milling.

Research on ultrasonic-assisted drilling in micro-hole machining of the DD6 superalloy

The DD6 nickel-based superalloy exhibits remarkably high temperature properties; therefore, it is employed as a crucial structural material in the aviation industry. Nevertheless, this material is difficult to process. Ultrasonic-assisted drilling (UAD) combines the characteristics of vibration processing technology and conventional drilling technology, significantly improving the machinability of difficult-to-machine materials. Thus, UAD experiments were performed on micro-hole machining of DD6 superalloy in this study. The effects of amplitude, frequency, spindle speed, and feed rate on thrust force, machining quality, and drill bit wear were studied; thereafter, a comparison was drawn between these effects and those of conventional drilling (CD). The experimental results reveal that the thrust force decreases with an increase in spindle speed or a decrease in feed rate for both UAD and CD. UAD can significantly reduce the thrust force. With the same processing parameters, the greater the amplitude, the greater the reduction of the thrust force. The surface roughness of the hole wall produced by UAD is lower than that of CD. Compared with CD, UAD reduces the burr height, improves machining accuracy, and reduces drill bit wear.

Effect of chip load and spindle speed on cutting force of Hastelloy X

Research on cutting force revealed that the cutting force decreases as cutting speed increases, which is in line with Salomon’s Theory. However, the fundamental behaviour was never clearly explained because most studies had focused on increasing the cutting speed by increasing spindle speed without retaining the rate of chip load. On that note, the effect of increasing spindle speed while chip load is constant on the cutting force of Hastelloy X is presented in this paper. Third Wave AdvantEdge software was applied and half-immersion up-milling simulations were conducted in dry condition. Result showed that the resultant force was primarily affected by the axial force, followed by normal force and feed force. Trend-lines indicated that the behaviour of cutting force components and resultant force was quadratic. Desirability Function Analysis (DFA) results revealed that the optimum combination of chip load and spindle speed led to lowest cutting force components and resultant force was at 0.013 mm/tooth and 24,100 RPM. Furthermore, the optimum cutting conditions that led to the lowest cutting force components and resultant force at chip loads of 0.016 mm/tooth and 0.019 mm/tooth was 24,100 RPM also. Therefore, increasing Material Removal Rate (MRR) while minimizing cutting force components and resultant force can be achieved by increasing the amount of chip load at spindle speed of 24,100 RPM.

Investigation of micromilled tool steel H13 using tungsten carbide micro-end mills

Micromilling allows for the high precision machining of different types of materials and thus promotes the manufacturing of micro-components for various technological applications. Evaluating tool wear in micromilling poses challenges not yet fully researched, more specifically the widely known size effect of micromilling processes contributes to an intricate cause-and-effect mechanism, and its research requires an understanding of the relationship of machining parameters in order to improve the process control. Thus, this paper researches the relationship between flank wear, feed, and specific cutting forces and roughness for the tool steel H13. Experiments with different levels of feed per tooth and spindle speed were carried out to measure and analyze tool flank wear, cutting forces, and the roughness of the workpiece. The lowest roughness value (Rz < 200 nm) was obtained for the feed per tooth of 2 μm at the beginning of the cut. However, this parameter also presented the highest flank wear, which led to the highest roughness value (Rz = 423 nm) at the final cutting length. Moreover, the interaction between the parameters feed per tooth and spindle speed occurs only at the maximum feed per tooth level. Increasing the feed per tooth to 5 μm and the spindle speed to 46,000 rpm significantly reduces flank wear. This behavior shows that not only increased feed rate but also increased spindle speed provided a combined reduction in plowing and improved shear mechanism.