Alumina Wheel Research Articles

A comprehensive investigation on eco-benign grindability improvement of Inconel 625 using nano-MQL

This work uses an alumina wheel to investigate the eco-benign grinding for better surface integrity of Inconel 625 (IN 625). To achieve this, applying nanofluids (NFs) with the minimum quantity lubrication (MQL) principle has been adopted, aiming at eco-benign grinding practices. In this work, MoS2 NFs, MWCNTs NFs and hybrid NFs (prepared by mixing MoS2 and MWCNTs in a 1:1 ratio) prepared using deionized water as the base fluid have been used. An in-house developed MQL setup is used to aim the NFs inside the grinding zone. The first attempt has been made to grind IN 625 in these environments. The characterisation of NFs in terms of nanofluid stability, dynamic viscosity, thermal conductivity and surface wettability have been performed before their utilization in grinding operations. A comparison has been made between the results obtained from NFs grinding and those from dry and soluble oil-based MQL grinding. It has been found that hybrid NFs provide excellent lubrication and cooling effects, reducing grinding forces and improving surface quality. Moreover, scanning electron microscopy, energy-dispersive spectroscopy and X-ray photon spectroscopy are applied to investigate the ground surfaces under different grinding conditions. Also, residual stress (with the help of X-ray diffraction and electron backscattered diffraction) and microhardness have been determined to gain further insights into the grinding behaviour. The wheel and chip morphology analyses have been performed to support the findings. The findings from this investigation lead to the conclusion that applying nano-MQL improves grinding effectiveness and promotes cleaner grinding outcomes. Hybrid NFs prove especially effective, as the physical synergistic effect enhances and safeguards the surface integrity of the produced ground components.

Multiscale simulation of volumetric wear of vitrified alumina grinding wheels

Wear of vitrified alumina wheels is a major research issue. Although extensive experimental work has been presented in the scientific literature, wheel manufacturers and grinding users are still unable to predict the expected grinding ratio of their operations. This work presents a novel multiscale approach that integrates the mechanical behavior of vitrified bonds with the stochastic nature of grain location. The new multiscale model integrates a DEM microscale model (μSM) and a randomization of the μSM (RμSM) of the wheel. The μSM simulates the stress field in the region of the wheel in contact with the workpiece, while RμSM accounts for the actual and random location of the alumina grits. This approach drastically reduces computational time and effectively determines the actual number of grains lost under a set of given grinding conditions. The model successfully predicts the detachment of complete clusters of abrasive grains from the bonds, with a large degree of agreement with experiments considering the deviation introduced by the micro-cutting edges that modify the hypothetical spherical geometry of the Discrete Elements (DEs). This is the first model to predict the volumetric wear of grinding wheels. The results will be useful for informing the future analysis of grinding operations affected by volumetric wear.

A comprehensive investigation of surface morphology during grinding of Inconel 625 using conventional grinding wheels

Grinding difficult-to-grind (DTG) materials such as superalloys have shown an upward trend for manufacturing high-precision and durable components. Superalloys, such as Inconel, have superior thermo-mechanical properties that allow them to withstand caustic working conditions and simultaneously make their grindability difficult. In this context, the present work investigates the grinding performance of Inconel 625 (IN 625) using conventional grinding wheels in dry condition. The current investigation uses the alumina wheel and the silicon carbide wheel to keep the cost factor minimum. The outcome of the experiments has been evaluated in terms of grinding forces and surface roughness. Advanced surface characterization techniques such as Scanning electron microscopy, X-ray diffraction, Raman spectroscopy and X-ray photoelectron spectroscopy have been employed to analyze the surface morphology of the ground surfaces produced by both wheels. It has been observed that the alumina wheel has performed much better than the silicon carbide wheel for a higher depth of cut. These observations have also been supported by wheel loading, in which loading for the silicon carbide wheel was approximately four times that of the alumina wheel. Moreover, long and flow types of chips produced by the alumina wheel indicate the better suitability of the alumina wheel while grinding IN 625. The findings of the present work are expected to provide an economical way of grinding IN 625, preferably using an alumina grinding wheel.

Grinding Force and Surface Formation Mechanisms of 17CrNi2MoVNb Alloy When Grinding with CBN and Alumina Wheels

The 17CrNi2MoVNb alloy is widely used for manufacturing heavy-duty gears in vehicles' transmission systems, where grinding is a significant process affecting gears' working performance and service life. This work comprehensively analyzed the grinding force, surface morphology, and surface roughness when grinding 17CrNi2MoVNb alloy using alumina and CBN grinding wheels. Results showed that the maximum normal grinding force from the CBN wheel was only ~67% of the one from the alumina wheel. Due to the small size and limited cutting depth of CBN grains, the grinding force increased by about 20% when the grinding depth increased from 0.02 to 0.03 mm for CBN grinding wheels. Surface defects, including cavities and material tearing, were mainly found on the ground surface when using an alumina grinding wheel. The surface roughness Ra recorded from the CBN grinding wheel mainly ranged from 0.263 to 0.410 μm, accounting for less than 40% of the one from the alumina grinding wheel. The information from this work could provide benchmark data and references for optimizing grinding tools and parameters when manufacturing gears in the vehicle industry.

Grinding characteristics of ultra-high strength steel by ultrasonic vibration-assisted grinding with microcrystalline alumina wheel

Grinding characteristics of ultra-high strength steel by ultrasonic vibration-assisted grinding with microcrystalline alumina wheel

Experimental Analyses into Dry Ultrasonic Vibration-Assisted Grinding of Difficult-to-Machine Tool Steel with Alumina Wheel

Experimental Analyses into Dry Ultrasonic Vibration-Assisted Grinding of Difficult-to-Machine Tool Steel with Alumina Wheel

On the grinding performance of alumina wheels in ultrasonic vibration–assisted grinding of hardened GCr15 steel

On the grinding performance of alumina wheels in ultrasonic vibration–assisted grinding of hardened GCr15 steel

Novel comparison concept between CBN and Al2O3 grinding process for eco-friendly production

Minimal Quantity of Lubrication was developed to achieve green manufacturing in machining process. In this study, parameters of cutting fluid flow, grinding wheel type and wheel cleaning system were evaluated to achieve the maximum potential of this technique in grinding process. The comparison of super abrasive (CBN) and conventional (Al2O3) grinding wheel, the cutting fluid flow (30 ml/h, 60 ml/h and 120 ml/h), and the wheel cleaning system were analyzed based on: surface roughness, roundness errors, grinding wheel wear, confocal of grounded surface, grinding power, acoustic emission and workpiece microscopy. In a novel way, this study compared the costs per piece and the carbon footprint in terms of CO2 emission for both abrasive tool application. For all the parameters analyzed, the CBN grinding with MQL outperformed the Al2O3 grinding, showing a superior performance not only in terms of surface finishing, on average, 29% lower surface roughness and dimensional deviation 9% lower but also regarding tool efficiencies, such as 127% lower diametrical wear, 42% lower acoustic emission, and 13% lower grinding power. Despite that, the cost per piece was also evaluated for the different lubri-cooling conditions and tools, and the cost per piece recorded for Al2O3 grinding was substantially lower than CBN grinding, irrespective of the lubri-cooling method employed. The cost of grinding for all MQL techniques analyzed with aluminum oxide wheel was, on average, 72% less than grinding with CBN wheel. Besides, the conventional method with the CBN wheel was 7% more expensive than the aluminum oxide wheel.

Novel performance assessment of interrupted grinding process using aluminum oxide wheel with resinoid bond

Novel performance assessment of interrupted grinding process using aluminum oxide wheel with resinoid bond

Study of the Use of Piezoelectric Diaphragm as a Low-Cost Alternative to the Acoustic Emission Sensor in Dressing Operation of Aluminum Oxide Wheels

Acoustic emission (AE) sensors have been widely used for tool condition monitoring in the grinding process. Recently, the piezoelectric diaphragm (piezoelectric buzzer) was introduced as a low-cost alternative for the same purpose. In this context, the present research work aims to study the efficiency of the piezoelectric diaphragm as a viable substitute to AE sensors in monitoring the dressing of structurally distinct aluminum oxide grinding wheels. Dressing tests were conducted using two industrial wheels, which were subjected to various dressing conditions. The signals generated by the AE and piezoelectric diaphragm sensors were collected simultaneously and subsequently analyzed in both time and frequency domains. The most relevant features related to the dressing were extracted through the following metrics: energy criterion, Pearson correlation coefficient, power spectral density (PSD), fast Fourier transform (FFT), and magnitude-squared coherence (MSC). Correlation greater than 80% was found between the piezoelectric diaphragm and AE sensor signals for determining the actual grinding wheel condition, which indicates the piezoelectric diaphragm as a viable alternative to the commercial AE sensors in dressing operation monitoring.

Industrial manufacturing linked to the mechanical and economic viewpoint of the mold steel grinding process using aluminum oxide wheel

Industrial manufacturing linked to the mechanical and economic viewpoint of the mold steel grinding process using aluminum oxide wheel

Grinding behavior of VP50IM steel using green and black silicon carbide compared to aluminum oxide wheel under different feed rates

Grinding behavior of VP50IM steel using green and black silicon carbide compared to aluminum oxide wheel under different feed rates

Influence of alumina abrasive tool wear on ground surface characteristics and corrosion properties of K444 nickel-based superalloy

K444 nickel-based superalloy is an important material to manufacture the gas turbine due to its excellent mechanical properties at high temperatures and corrosion resistance. Currently, grinding is the mostly used method for the surface finish of the K444 alloy components. However, few studies worked on the effects of the abrasive tool wear on the ground surface characteristics and corrosion properties of K444 alloy. This study uses two different-type alumina abrasive tools, i.e., white alumina (WA) and microcrystalline alumina (MA) wheels, to grind the K444 alloy. The influence of the alumina abrasive tool wear on ground surface characteristics and corrosion resistance performance are investigated. It is discovered that the MA wheel presents a slighter wheel wear and higher self-sharpening than the WA wheel. Compared to the WA wheel, the MA wheel has less material adhesion, which leads to a better surface finish. In the corrosion testing, the maximum corrosion depth is 80 μm in the surface ground by the MA wheel but 100 μm in the surface ground by the WA wheel, which demonstrates that the MA wheel grinding benefits the surface corrosion resistance of K444 alloy. Therefore, this study could provide a guide to selecting the abrasive tools and optimizing the grinding process of the K444 alloy.

On the tool wear behavior during ultrasonic vibration-assisted form grinding with alumina wheels

Ultrasonic vibration-assisted form grinding (UVAFG) with alumina wheels has become a potential technology to machine the areo-engine blade root. In this work, the characterizations of wear patterns of grinding wheel surface morphologies, such as clogging, grain micro-fracture and pull-out, were performed under conventional form grinding (CFG) and UVAFG methods, respectively. In addition, the comparative grinding performances, including grinding forces and force ratio, protrusion height distribution of worn grains, ground surface quality for both grinding methods, were discussed. The results indicate that the tool clogging and grain pull-out under UVAFG method can be effectively improved compared to CFG method. More excellent sharpness ability of alumina wheels under UVAFG can be obtained due to the grain micro-fracture by high frequency impacting between tool and workpiece. Furthermore, the alumina wheels under UVAFG possess lower grinding forces, larger protrusion height values of worn grains, and better ground surface quality in comparison of the other grinding method.

On grinding force ratio, specific energy, G-ratio and residual stress in SQCL assisted grinding using aerosol of MWCNT nanofluid

In the present investigation, water based multi-walled carbon nanotube (MWCNT) dispersed nanofluid was produced and used as a cutting fluid in small quantity cooling lubrication (SQCL) assisted grinding of hardened AISI52100 steel. The work material was ground by an alumina wheel. The SQCL technology utilizes atomized aerosol of liquid grinding fluid. Use of MWCNT nanofluid aerosol in place of soluble oil was found to be substantially beneficial in reduction of specific energy and development of compressive residual stress on ground surface. The steady and lower value of the force ratio (tangential to normal grinding force, Ft/Fn) was suggestive of the superior lubrication and grit sharpness retention ability of the aerosol of MWCNT nanofluid. Higher compressive residual stress on the ground surface under MWCNT nanofluid environment suggests lesser grinding zone temperature, which can be attributed to its superior wettability, lubricity and heat dissipation ability of the MWCNT nanofluid. The consumption rate of grinding fluid in SQCL was varied. It could be reduced to 200 ml/h for MWCNT nanofluid to obtain an almost similar or better effect to that of 500 ml/h for soluble oil. Lesser surface tension of MWCNT nanofluid, compared to its counterpart, seemed to facilitate wetting, thus improving lubrication and heat transfer capability further.

A 3D analytical thermal model in grinding considering a periodic heat source under dry and wet conditions

Predicting the temperature distribution in the workpiece is of high importance to control and prevent thermally induced damages in grinding. Grinding force has an oscillating nature because of the discrete grit-workpiece interaction. The force fluctuation is more pronounced in macro level when the wheel vibrates due to run out or when segmented, grooved or pattern wheels are utilized. These fluctuations cause a discontinuous or a time-dependent heat source. In this study, the dynamic part of the heat source is included in an analytical thermal model as a new approach to understand detailed workpiece temperature behavior in grinding. Furthermore, heat convection from side surfaces of the workpiece was not included in previous analytical models and is formulated and discussed in this study for the first time. By considering proper boundary conditions an analytical solution for the workpiece temperature distribution by using the periodic heat source concept is proposed. The influential parameters are discussed theoretically, and it is shown that the heat source fluctuations cause an increase in maximum temperature compared to the case with a constant heat source. Furthermore, it is shown that the 2D solution is quite reliable and precise enough to predict the maximum temperature of the slab workpiece having a long width in both wet and dry conditions. Grinding experiments have been carried out to validate the model accuracy by embedding foil thermocouples in a split workpiece setup while using CBN electroplated and aluminum oxide wheels. Validation of discontinuous heat source model was investigated while the wheels have some run out. The effects of grinding conditions on the maximum temperature have been obtained experimentally and compared with the proposed model. The results show that considering a time-dependent heat source not only explains and predicts the cyclic nature of temperature but also improves the prediction of workpiece temperature accuracy.

Advances in precision manufacturing towards eco-friendly grinding process by applying MQL with cold air compared with cooled wheel cleaning jet

With the evolution of the sustainable industry, the grinding process seeks to follow the requirements to continue to be highly employed when precision and low-dimensional tolerances are required in the workpieces. In this way, the cutting fluids used in the process, which are essential for a good surface finish, are the main impasse to ensure that the process becomes eco-friendly. Therefore, a widespread lubri-refrigeration method in the industry is the flood technique, which uses a lot of fluid to reduce the high temperatures generated during grinding. However, the use of the flood method generates many undesirable residues that affect the machine operator, the environment, and production costs. Thus, several alternatives have emerged to address these problems, for example, the minimum quantity of lubricant (MQL), the wheel cleaning jet system (WCJ), and the application of cooled air (CA). Therefore, this work sought to analyze the combination of these systems (MQL+CA, MQL+WCJ, and MQL) in the grinding of AISI 4340 steel using an aluminum oxide wheel (Al2O3) and to verify their performance compared with the flood method, in addition to employing a new method known as cooled wheel cleaning jet (CWCJ). Therefore, the tests of surface roughness (Ra and Rz), roundness error, diametrical wheel wear, G ratio, grinding power, tangential cutting force, and microhardness were performed, and optical, confocal, and scanning electron microscopy also were analyzed. Thus, the results that came closest to the flood method in all tests were achieved by systems that applied grinding wheel cleaning (MQL + WCJ and MQL + CWCJ), being that in the diametrical wheel wear and G ratio the MQL + CWCJ even managed to surpass it. Besides, the MQL+CA union showed better values when compared with MQL without any assistance. Thus, applying MQL with helper systems, mainly CWCJ, contributed to a more economical, efficient, and sustainable grinding process.

Grinding comparative analysis between different proportions of water-oil applied to MQL technique and industrial production cost towards a green manufacturing

The high temperatures involved in the grinding process require an efficient lubri-refrigeration method. Currently, the conventional method (flood) is the most used in industries. However, this method comes up against environmental damage and the health of operators, due to high amounts of fluid injected into the cutting region. Therefore, the use of the minimum quantity lubricant (MQL) technique with a wheel cleaning jet (WCJ) proves to be a viable alternative. This work makes a comparative analysis of the MQL + WCJ system with a conventional method. In this sense, the experiments grinding the AISI 4340 steel with an aluminum oxide wheel. The lubrication and cooling of the process were done by the conventional method, pure MQL, and diluted MQL (oil-water 1:1, 1:3, 1:5) with and without cleaning (WCJ). The output parameters evaluated were surface roughness (Ra), roundness error, G-ratio, tangential cutting force, specific energy, microstructure, and cost. The surface roughness shows an increase of only 18%, with the use of the MQL technique diluted 1:5 + WCJ compared to the conventional method. Also, the implementation of the MQL technique is cheaper than the conventional method. The results show that the addition of water in MQL favors grinding, and the efficiency of MQL increases when associated with WCJ for all parameters.

Systematic Monitoring and Evaluating the Wear of Alumina Wheel When Grinding the Workpiece of Cr12

The performance of the grinding wheel demonstrably affects the machining efficiency and the quality of the workpiece. Therefore, it is essential to evaluate the wear of the wheel and then operate the dressing or replacement in time. The wear procession of the wheel was monitored and evaluated systematically in this paper. A surface grinding experiment was performed by using an alumina wheel to grind the workpiece made of Cr12. The grinding force and the grinding temperature were monitored and measured while the wheel grinds the workpiece. The surface topography of the wheel was also being observed. The distribution of the gray value of pixels in the image of the wheel surface was analyzed by the method of the histogram. Processing of the binary image of the wheel was performed after determining the gray threshold of the gray value. Then, the blockading and the wearing area on the grinding wheel were calculated. Moreover, the relation of the projection area of a single abrasive derived from theory and derived by image recognition was studied. The results of the grinding experiment show that wheel performance degradation occurs when the material removal volume reaches 210 mm3/mm. At this time, the ratio of blockage area on the grinding wheel reaches 13.4%. The percentage of the wearing area is 9.5%. The method of image recognition combined with grinding temperature is workable to realize monitoring and evaluating the wear of wheels on site without unloading them.

New knowledge about grinding using MQL simultaneous to cooled air and MQL combined to wheel cleaning jet technique

The final quality of mechanical components has been increasingly desired in the industry. This final quality is directly linked to surface roughness, geometric deviations, and mechanical integrity of components subjected to machining processes. For that, the industry makes use of cutting fluids so that it is possible to achieve such conditions. In the case of grinding, the application of cutting fluid in abundance allows a great reduction in temperature, as well as a better removal of chips from the cutting surface of the wheel. However, the problems generated by the cutting fluid related to environmental and labor liabilities have increasingly led to the development of effective techniques for grinding with minimal amounts of cutting fluid. The difficulties linked to the use of MQL are concentrated in the low rate of heat removal and in the clogging of the cutting surface, varying according to the type of grinding wheel applied. In this sense, the present work proposes comparison during the cylindrical grinding of hardened steel under conventional lubrication conditions, minimum quantity lubricant (MQL), cooled air MQL (MQL + CA), and MQL with wheel cleaning jet (MQL + WCJ), using aluminum oxide (Al2O3) and CBN grinding wheels. The results are presented in terms of surface roughness, roundness error, microhardness, tangential force, diametrical wear of the grinding wheels, and G-ratio. The application of MQL + CA and MQL + WCJ can improve the use of MQL. In terms of roughness, the MQL + WCJ presents values close to the conventional increase of 8.8%. Roundness errors were reduced by up to 36.3% during the application of MQL + CA and MQL + WCJ and up to 10.5% for the tangential force. Thus, these advanced techniques have shown that the conditions are feasible for the application of pure MQL towards an eco-friendly grinding process.