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The purpose of this study is to comparatively investigate the wear behavior of nickel-based superalloy surfaces induced by mechanical polishing and grinding using the contact fretting against YG6 cemented carbide balls. Experimental results indicate that the friction coefficient and wear volume of the ground surface of nickel-based superalloy are smaller by 7.3% and by 18% on average, respectively, than those of the polished one. Furthermore, the high fretting wear loss of polished nickel-based superalloy can be attributed to the wear recirculation process composed of the plastic deformation, oxidization wear, surface and subsurface micro crack, which eventually leads to the significant material peeling and fatigue delamination. However, the ground nickel-based superalloy presents mainly the abrasive wear and excellent fretting wear-resistance due to the high hardness induced by grinding and the completely continuous compacted debris layer with few cracks instead of the ground surface to contact with the counterpart ball. Obtained results are beneficial for deepening the understanding of degradation mechanism during fretting of the nickel-based superalloy surfaces prepared by mechanical grinding and polishing. [ABSTRACT FROM AUTHOR]

Gradient structures have been created in single crystal nickel-based superalloys (SX alloys) via surface mechanical creep-feed grinding treatment (SMCGT). It has been found that these gradient structures are mainly composed of nano-sized grains, sub-micron-sized grains, dislocation structures, and the matrix material of single crystals along the depth from the treated surface. In addition, the evolution of such structures is found to be dominated by the dislocation movements which run through both γ channels and γ' precipitates, subdividing the two types of microstructures into various dislocation structures, and eventually introducing the refined grains into the surface layer. Furthermore, the evolution process of gradient structures primarily originates from the mechanical effect between abrasive grits and workpiece material, owing to the large grinding force (up to 529 N) and low grinding temperature (less than 150 °C) during the unique creep-feed grinding treatment in the present investigation. Due to the typical grain refinement, the hardness of the nanostructures exhibits the largest value of around 10 GPa in the surface layer, approximately 26% higher than that of the matrix material. This study further enhances the understanding of the microstructure–property relationship of SX alloys subjected to creep-feed grinding treatment and contributes to achievement of high-performance components. [ABSTRACT FROM AUTHOR]

Ultrasonic vibration-assisted grinding (UVG) is a promising precision machining method for difficult-to-cut materials. This study investigated the intermittent cutting behavior in UVG of Inconel718 nickel-based superalloy and its effect on the grinding temperature, grinding force and workpiece surface quality. A novel material removal probability model was established to analyze the impact depth and the contact length between the abrasive grain and the workpiece considering the interference of grinding trajectories in UVG. Results indicated that the intermittent cutting behavior in UVG caused a decrease in the contact length by 42%, resulting in a significant reduction of grinding temperature and grinding force by 40% and 41%, respectively. It was suggested that the increase in the cutting depth was better than the increase in the workpiece infeed speed for enabling the lager material removal rate in the tangential UVG due to the lower grinding force ratio and the less change of specific grinding energy. A specific surface texture was generated on the ground surface due to the phenomenon of frequent contact and separation, enabling the reduction of workpiece surface roughness by maximum 20%. • A novel material removal probability model is established to analyze intermittent cutting behavior. • The contact length between tool and workpiece was decreased by 42% due to the intermittent cutting behavior. • Maximum material removal rate in ultrasonic grinding is three times of that in conventional grinding. • Grinding forces in ultrasonic grinding decreases by 41% compared with conventional grinding. • A specific surface texture is generated on ground surface enabling the reduction of surface roughness by 20%. [ABSTRACT FROM AUTHOR]

Grinding force has an important impact on the ground precision and quality of a workpiece. At present, the effects of the workpiece structure and the change in the abrasive wheel diameter on grinding force are ignored during profile grinding. Therefore, to reduce the grinding force and improve the grinding integrity, profile grinding experiments were conducted on the structure of FGH96 turbine disc slots (TDS) using an electroplated cubic boron nitride (CBN) abrasive wheel. The built grinding force model was evaluated. The influences of the grinding parameters on the grinding force were determined through absolute sensitivity analysis. In addition, the grinding force affected by the slot structure was also studied. Results show that the average errors of the radial and tangential profile grinding forces were 12.8% and 13.4%, and the standard deviation of errors were 5.4% and 5.9%, respectively. The absolute sensitivity of the profile grinding force to the workpiece infeed speed and the depth of cut was positive and that to the abrasive wheel speed and diameter was negative. Furthermore, the grinding forces varied at different positions of slots ground surface. According to the standard deviation, the larger grinding parameters is, the larger dispersion degree of the grinding force will be. The results could provide significant guidance for parameter selection or optimization. [ABSTRACT FROM AUTHOR]

Ultra-high-speed grinding is a significant method for the advanced manufacturing of the difficult-to-machine material components, e.g., nickel-based superalloy. However, unclear mechanism of material removal behavior is still the main problem. The present work intends to establish the three-dimensional (3D) finite element simulation model of ultra-high-speed grinding with single abrasive grain. The effects of undeformed chip thickness and grinding speed on the morphology of grinding traces and chips are investigated. The parameters, such as pile-up ratio and shear slip frequency, are characterized experimentally, and the mechanism of material removal behavior in the process of ultra-high-speed grinding has been accordingly researched deeply. The results indicate that the pile-up ratio decreases firstly and then increases with an increase of undeformed chip thickness; the lowest pile-up ratio would be obtained when the undeformed chip thickness is 0.8~1 μm. When the grinding speed is below 240 m/s, with the increase of grinding speed, the distance between the sawtooth of the grinding chips is reduced, while the sawtooth degree is increased. When the grinding speed exceeds 400 m/s, the chip shape changes from serrated fracture to banded continuity, and the frequency of adiabatic shear slip goes up with the increase of grinding speed, which helps to reduce the grinding force, making the grinding process more stable and decreasing the difficult machinability of Inconel 718 nickel-based superalloy. [ABSTRACT FROM AUTHOR]

This study investigates the comparative wear behavior of brown alumina (BA) and microcrystalline alumina (MA) alumina abrasive wheels and its effect on the creep feed ground surface of different nickel-based superalloys, such as wrought alloy GH4169, directional solidified alloy DZ408 and single crystal solidified alloy DD6. The abrasive wheel wear topography was characterized and an analytical model was developed to evaluate the abrasive wheel wear comprehensively. Finally, the effects of tool wear on the grinding performance and ground surface were discussed. Results obtained indicate that, compared with BA abrasive wheel, the MA wheel performed better in terms of the grinding ratio and tool wear behavior. Strong adhesion wear and attritious wear of the abrasive wheels were generated during grinding of GH4169 and DZ408 alloys, while great wheel clogging occurred during grinding of DD6 alloy. Moreover, DZ408 alloy produced the most severe tool wear and largest grinding forces, followed by GH4169 and DD6 alloys. The defects pattern of ground surface with BA wheel was unparallel to the grinding direction due to the grain dislodging and fracture; however, when grinding with MA wheel, groove defects were created along the grinding direction due to high ductility and hardness of grains. • Microcrystalline alumina abrasive wheel performed better than brown alumina wheel. • DZ408 alloy has the highest grinding difficulties, followed by GH4169 and DD6 alloys. • Adhesion wear of alumina abrasive wheels happened during grinding GH4169 and DZ408. • Clogging wear of alumina abrasive wheels occurred during grinding DD6. • The abrasive wheel wear changes from attritious wear to fracture wear in creep feed grinding. • Ground surface defects are produced due to dislodged and fractured grains of abrasive wheels. [ABSTRACT FROM AUTHOR]

Cubic boron nitride (CBN) superabrasive wheels are of great potential in grinding of difficult-to-machine metallic materials. The grain wear and its evolution directly determine the sharpness of the grinding wheels, and therefore greatly affect the grinding efficiency, surface integrity and the tool life. In order to effectively control the grain wear, the present work is aimed to elucidate the wear behavior difference of polycrystalline CBN (PCBN) abrasive grains and conventional CBN grains, and meanwhile analyze the influence of grinding wheel speed (ranged from 20 to 120 m/s) on the PCBN grain wear. The wear behavior was also quantitatively characterized based on the fractal theory. Results obtained show that the self-sharpening ability of PCBN grain is superior to CBN grain considering the fractal dimension and specific grinding force. The radial wear and specific grinding force with the grinding wheel speed of 120 m/s increase severely by 29.6% and 117.3% compared with that of grinding wheel speed of 80 m/s, which is in accord with the change of fractal dimension. When considering the wear evolution behavior of PCBN grains, a critical grinding wheel speed, e.g., 80 m/s, could be determined. If the grinding wheel speed is above 80 m/s, the grain macro-fracture wear happens rapidly; however, if it is below 80 m/s, the grain micro-fracture wear increases with increasing of the grinding wheel speed. According to the finite element analysis, the micro-fracture of the PCBN grain is mainly caused by the intergranular fracture of the grain, while the attritious wear is due to the wear of the grain cutting edge. • Single grain grinding tests are conducted to analyze PCBN grain wear. • The grain wear is evaluated quantitatively by fractal dimension. • Self-sharpening ability of PCBN grain is verified through grinding force signal. • Micro-fracture and attritious wear are the main wear patterns of PCBN grain. • The best cutting ability is obtained when grinding wheel speed is 80 m/s. • Micro-fracture of PCBN grain is caused by the intergranular fracture. [ABSTRACT FROM AUTHOR]

The grindability and sensibility analysis of surface roughness of powder metallurgy nickel-base superalloy FGH96 were studied in comparison to the wrought nickel-base superalloy GH4169. The effects of grinding parameters (such as workpiece infeed speed, depth of cut, and abrasive wheel speed) on grinding force, grinding temperature, specific grinding energy, abrasive wheel wear, and surface roughness were analyzed. The results show that the grinding force, grinding temperature, and specific grinding energy of GH4169 are usually higher than those of FGH96 under the given experimental conditions. However, the wear behavior of the brown corundum abrasive wheels when grinding these two kinds of nickel-base superalloy material is generally identical. The sensitivity of GH4169 workpiece surface roughness to depth of cut and workpiece infeed speed is higher than that of FGH96, but the sensitivity of GH4169 to abrasive wheel speed is less than that of FGH96. Finally, it is inferred that the grinding performance of FGH96 is slightly better than that of GH4169. [ABSTRACT FROM AUTHOR]

DD6 nickel-based single-crystal superalloy has been treated as an ideal material for the high-valued and high-performed aero-engine components; however, it was found difficult to remove material from the DD6 nickel-based single-crystal superalloy in cutting and grinding. Although creep-feed deep grinding (CFDG) has been widely employed for various nickel-based superalloys (i.e., Inconel 718, DZ4, IN738LC), very few efforts however have been focused on the nickel-based single-crystal superalloy. With this, this paper focuses on CFDG of DD6 nickel-based single-crystal superalloy to gain the more in-depth understandings, targeting grinding force, specific grinding energy, grinding temperature, surface integrity, and wheel wear condition. Scheduled experimental observation proved that (i) microcrystalline alumina abrasive wheel generally shows more superior grinding performances in aspect to grinding force, force ratio, and specific grinding energy than that of brown alumina abrasive wheel; (ii) grinding temperature is decreased by 35% by using the microcrystalline alumina abrasive wheel compared to brown alumina abrasive wheel, and therefore the microcrystalline alumina abrasive wheels have the potential to be applied in the high-efficiency grinding; (iii) the surface ground by the microcrystalline alumina abrasive wheel is found smooth without any grinding-induced damage; and (iv) microcrystalline alumina abrasive wheels easily lead to micro-fractures and therefore result in better self-sharpness ability and longer service life in CFDG of DD6 nickel-based single-crystal superalloy. [ABSTRACT FROM AUTHOR]

This article aims at providing a fundamental performance evaluation when grinding TiAlNb intermetallics using SiC abrasive. The wheel speed is fixed at 20 m/s while a range of depth of cut (5-20 μm) and workpiece infeed speed (3-12 m/min) are applied. For better understanding, two kinds of common difficult-to-cut materials, i.e., Ti-6Al-4V titanium alloy and Inconel718 nickel-based superalloy are also ground to form a comparison. As for the equal grinding parameters, the normal and tangential grinding forces of TiAlNb intermetallics are found to be about twice of those of Ti-6Al-4V alloy, and be only a third and a half of those of Inconel718 alloy, respectively. In addition, TiAlNb intermetallics shows more severe tool wear and associated lower G-ratio compared to Inconel718 alloy as a result of strong affinity for SiC abrasives. For the surface integrity, TiAlNb intermetallics reveal the same ground surface roughness level, i.e., 0.3-0.6 μm for the applied grinding parameters, with Ti-6Al-4V alloy and Inconel718 alloy. A white layer is easily formed during grinding of TiAlNb intermetallics, which adversely affects the machined surface integrity. [ABSTRACT FROM AUTHOR]

In order to explore the effect of undeformed chip thickness (UCT) on the grain wear behavior, the single grain grinding experiment was carried out on the typical difficult-to-cut material, such as nickel-based superalloy Inconel 718. The grinding forces of single grain were measured, and the grain wear morphology was also characterized under different UCT values. The variations of grain wear behavior, grinding forces, and radial wear of single grain were investigated under the conditions of UCT range from 0.2 to 1 μm. The results show that size effect could change the grain wear behavior in grinding. In the beginning of wear, the crescent depression is observed on the rake face at each value of UCT. As the grain wears more seriously, the crescent depression would change into a new rake face or new cutting edge. Besides, with the increase of specific material removal volume (SMRV), the grinding forces tend to increase firstly and then remain stable under different UCT values. Furthermore, the size effect of grain wear behavior also takes effects on the grinding force ratios. The quantitative analysis of radial wear further proves that size effect leads to the change of grain wear amount in grinding. [ABSTRACT FROM AUTHOR]

High-efficiency deep grinding experiments of nickel-based superalloy Inconel718 were conducted with a vitrified cubic boron nitride wheel. An investigation was made to detect the relationship between the undeformed chip thickness and grinding temperature and burn-out behavior of the workpiece material. The results display that the grinding forces and grinding power increase with the increase of the undeformed chip thickness. When the coolant is in the nucleate boiling state, the grinding temperature keeps stably at below 140 °C; however, the grinding temperature increases rapidly to the materials burn-out point once the coolant enters the film boiling state. The critical range, 0.65 ∼ 0.75 μm, is determined for the undeformed chip thickness under the defined experimental condition, which could take a great effect on controlling the grinding burn-out and increasing the grinding efficiency. [ABSTRACT FROM AUTHOR]

This paper provides a state-of-the-art review on the investigations into the residual stresses in metallic structural materials generated by grinding. The materials covered include steels, titanium alloys, and nickel-based superalloys. The formation mechanisms of the residual stresses and their impacts are specifically discussed. Some major influential factors on the residual stresses formation in grinding, such as grinding wheel characteristics, dressing techniques, grinding parameters, cooling conditions, and properties of workpiece materials, are analyzed in detail. These include experimental measurement, modeling, simulation, knowledge-based monitoring, and fuzzy analysis. Finally, the paper highlights some important aspects of grinding-induced residual stresses for further investigation. [ABSTRACT FROM AUTHOR]

In order to explore the effect of grain wear on material removal behavior during grinding nickel-based superalloy Inconel 718, the grinding experiment with a single diamond grain was carried out. The variations of grain wear, grinding force and force ratio, and pile-up ratio were investigated under the conditions of undeformed chip thickness (UCT) ranging from 0.2 to 1 µm. The results show that a critical UCT value, such as 0.3 µm, could be determined according to the pile-up ratio and could also be used to quantify the material removal process. The wear behavior of a diamond grain shows four types, such as crescent depression on the rake face, abrasion on the flank face, grain micro-fracture, and grain macro-fracture. Furthermore, these classifications are determined by the dwell time of rubbing, ploughing and cutting at different UCT values applied. The grinding force ratio increases with increasing of the negative rake angle of a diamond grain. In the rubbing and ploughing stages, the material removal efficiency is proportional to the wear width on the rake face. However, in the cutting stage, the material removal efficiency is diminished in the absence process of crescent depression. [ABSTRACT FROM AUTHOR]

[Display omitted] • Gradient microstructures including nanograins, submicron grains, and dislocation structures were induced in SX alloy by creep-feed grinding. • Indentation hardness and elastic modulus of gradient structures were higher by 8–10% than bulk material. • The topmost layer containing nanograins is unfavorable to enhance creep performance. • Dislocation activities in ground layer dominate the indentation creep deformation. The gradient microstructures of surface layer in single crystal nickel-based superalloy were produced by creep-feed grinding. The mechanical properties (i.e., hardness, elastic modulus) and room-temperature (RT) creep behavior of such structures were evaluated using a nano-indentation technique. Results show that the gradient structures along depth from ground surface consisted of nanograins, submicron grains and lamellar-shape structures, and dislocation structures. Furthermore, it was found that the hardness and elastic modulus of gradient structures were higher by 8–10% than that of bulk material on average. However, the regions containing nanograins showed a remarkable increase in creep depth compared to bulk material, implying that the creep behavior of ground layer was changed unfavorably. The obtained stress exponents of gradient structures suggested that dislocation activities were the main mechanism for indentation creep deformation. [ABSTRACT FROM AUTHOR]

Different aspects on the tool wear behavior of profiled vitrified microcrystalline alumina wheels during creep feed grinding of Ni alloy blade root were investigated. Experimental results indicate that the wheel peak regions had the higher wear values than the wheel valley regions by around 21.7%, 42.8%, 34.5%, in terms of the profile heights, circle radii and angles respectively. Furthermore, the wear flats, workpiece material adhesion, and the fractures of grains and bond bridges occurred in the wheel peak regions; while in the wheel valley regions, heavy wheel clogging, fractures of grains, and workpiece material adhesion were produced. Based on the experimental results, an analytical model with the average error of 17.3% to predict the wheel profile wear was finally developed. • Profiled alumina wheel wear in creep feed grinding of Ni alloy blade root was examined. • The wheel peak region had the higher profile wear than the wheel valley region. • Workpiece speed and sliding length of individual grain greatly affected grinding ratio. • Wear flat and fracture occurred for wheel peak region while clogging for valley region. • Analytical model with the error of 17.3% was developed to predict wheel profile wear. [ABSTRACT FROM AUTHOR]

Abstract In this study, both finite element analysis (FEA) and experimental observations were used to investigate the single CBN grain wear in high-speed grinding of Inconel 718 superalloy. The wear characteristics for each grinding pass were numerically assessed utilizing the tensile and compressive strength limits of the cutting grain. Additionally, stress distribution within the grain, chip formation and grinding force evolution during multiple passes were investigated. The combined experimental and numerical results show that the CBN grain wear has two major modes: the macro fracture on the grain top surface propagating from the rake surface, and the micro fracture near the cutting edges. The resultant tensile stress is the main factor inducing grain wear. The cutting edges will be under self-sharpening due to the grain wear. With multiple micro cutting edges engaged in grinding process, the limited material removal region was divided into different sliding, ploughing and cutting dominant regions. Overall, the ratio of material elements removed by a cutting process ranges from 80% to 20%, and continue to decrease during the grinding process. With a stronger effect of the cutting process, larger fluctuation of the grinding force will commence, however its average value remains below that with stronger sliding and ploughing process characteristics. Highlights • CBN grain rake surface macro fracture and cutting edge micro fracture have been found. • The crack propagation within grain is mainly caused by tensile stress. • Multiple cutting edges are under self-sharpening and engaged in grinding due to the grain wear. • Single CBN grain morphology evolution has been predicted according to grain fracture. • Sliding and ploughing induced grain chipping and grinding force increased with grain wear. [ABSTRACT FROM AUTHOR]

Cubic boron nitride (CBN) has high hardness and superior thermal conductivity, and it was used to fabricate an oscillating heat pipe abrasive wheel (OHPGW) for the eco-benign grinding of hard-to-machine materials. Furthermore, the wear behavior of the CBN grains and the related lifecycle of the OHPGW are important. In this study, a comparative analysis was conducted to reveal the wear behavior of CBN grains on OHPGWs and conventional wheels. Under the enhanced heat transfer effect of the OHPGW, the CBN grain wear behavior, development of the CBN protrusion heights, and the ground surface quality were investigated. The CBN grains on the abrasive wheel experience initial, stable, and fast wear periods in conditions of attrition, micro-fracture, and macro-fracture. Owing to the low grinding heat and temperature acting on the OHPGW, the CBN grains mostly undergo attrition during the stable period, while CBN grains on the conventional wheel mainly undergo micro and macro-fractures. As the wear of the CBN grains progressed, the average protrusion height of the CBN grains decreased. The scattering of the protrusion height distribution decreased at first and then increased when entering the fast wear period. Consequently, the surface topography and roughness initially improved and then deteriorated with the development of the protrusion height distribution of the CBN grains. [ABSTRACT FROM AUTHOR]

The GH4169D superalloy, a novel Nickel-based material widely acknowledged for its exceptional high temperature strength and fatigue resistance properties, plays a pivotal role in the production of critical components of contemporary aero-engines. The material, however, falls under the category of a typical difficult-to-cut metallic material due to the substantial cutting forces and significant tool wear experienced during the machining process. In this paper, a method of longitudinal ultrasonic vibration assisted side milling (LUVM) was developed to extend tool life. The investigation primarily involved an analysis of tool wear behaviors, including milling force, tool life, morphologies of tool wear, and various underlying wear mechanisms in LUVM and conventional milling (CM) of GH4169D superalloy. The results demonstrate that LUVM exhibits the advantage of reducing milling forces and prolonging tool life in comparison to CM. Throughout the entire milling process, the maximum milling force of LUVM is consistently smaller than that of CM, displaying a comparatively slower growth trend. At the conclusion of machining, while CM reaches a maximum milling force of 360.3 N, the maximum milling force of LUVM (195.9 N) is significantly lower. The tool life of LUVM is 28.2 min, representing a 33 % increase compared to CM (21.2 min). Material adhesion, coating delamination, and built-up edge (BUE) phenomena can be observed on both the tool rake face and flank face in CM. LUVM contributes to mitigation of bonding phenomena, prevention of BUE formation, and avoidance of abrasive wear in comparison to CM. However, it is prone to lead to tool tip chipping. For CM, the tool wear mechanisms include adhesive wear, oxidation wear, abrasive wear and diffusion wear; whereas for LUVM, the tool wear mechanisms comprise of adhesive wear, oxidation wear and diffusion wear. [Display omitted] • LUVM exhibits the advantage of reducing milling forces and prolonging tool life compared to CM. • LUVM contributes to mitigation of bonding phenomena and prevention of BUE formation compared to CM. • Adhesive, oxidation and diffusion wear patterns are identified as the tool wear mechanisms for LUVM. [ABSTRACT FROM AUTHOR]

• An analytical model of abrasive wheel wear in UVAPG is built. • Model considers unchanged chip thickness and grinding trajectory interference. • The variation of active abrasive grains in UVAPG is revealed. • Effects of abrasive wheel profile on the wear characteristics is interpreted. Blade root with a special fir-tree shape is a critical connection part in an aero-engine. This part has high requirements on the surface finish and geometrical accuracy. At present, the tangential ultrasonic vibration-assisted profile grinding (UVAPG) is an effective method for machining the blade roots. During UVAPG, the wheel wear degrades the surface finish and geometrical accuracy. However, the characteristics of the wheel wear in UVAPG are not fully revealed. This study proposes an analytical wear model by considering the intermittent grinding behavior of a grinding edge, the number of active grinding edges, and the effects of wheel profile on the tool wear. The model is experimentally demonstrated to be applicable to predicting the wear volume in UVAPG with a maximum error of 4.2 %. Based on the model, the tangential ultrasonic vibration increases the average unchanged chip thickness and the number of active grinding edges. UVAPG causes an approximately 22 % increase in wear volume at the steady wear stage compared with the conventional grinding. The wear speeds vary at different regions of a profile wheel. The convex regions represent higher wear speeds than the concave regions on the wheel. [ABSTRACT FROM AUTHOR]

The grain wear evolution during grinding powder metallurgy superalloy FGH96 using a single abrasive grain of cubic boron nitride (CBN) under different undeformed chip thickness and abrasive wheel speed was investigated. The wear behavior of single abrasive grain (SAG) was extracted based on the variation feature of grinding force, radial wear, grain topography and material remove characteristics. Meanwhile, acoustic emission (AE) testing is used to analyze the grain wear evolution. The results show that micro fracture firstly occurs at the original defects of SAG at the initial wear stage. Attrition wear and micro fracture are responsible for the steady wear stage, while micro and macro fracture are dominant at severe wear stage. Besides, the manner of the plastic adiabatic shear remove occurs in the process of grinding FGH96. Furthermore, sudden increase of root mean square (RMS) of AE signal can be applied to reflect the fracture of SAG, whereas the continuously gradual decrease can be considered the attrition wear or material adhesion, which can provide a technical support for monitoring the grain wear during grinding. [ABSTRACT FROM AUTHOR]

Inconel 718 nickel-based superalloys are important aerospace materials whose precision surfaces have important applications in key aerospace components. It is significant and challenging to obtain precise surfaces of Ni-based superalloys with high efficiency and quality. Plasma electrolytic polishing (PEP) is a rapidly developing high-efficiency and high-quality metal surface polishing process and is an application process for obtaining precise surfaces of superalloys. Research on the influence of vapor gaseous envelope (VGE) behaviors and the evolution process on the polishing effect remain insufficient, although the behavior of the VGE affects the machining efficiency and surface morphology of the superalloy. In this study, the evolution process of the VGE was analyzed and simulated using experimental and simulation methods. The effects of the VGE behavior characteristics on the surface morphology and polishing efficiency were explained from the perspective of energy distribution. The experimental results showed that a discontinuous and fluctuating VGE favored the removal of materials and finishing of the workpiece surface. When the voltage exceeded 400 V, the heat flux at the gas-liquid interface exceeded the critical heat flux, and the VGE evolved from bubbles to a vapor film which deteriorated the polishing effect. Finally, the voltage range for obtaining the precision surface of the superalloy was 250–350 V, while the temperature range of the electrolyte was 70–85 °C. • Plasma electrolytic polishing was successfully performed on Inconel 718 alloy. • The VGE evolution in the polishing process was modeled and simulated. • Behaviors of the vapor gaseous envelope (VGE) determine the polishing effect. • The heat flux at the gas-liquid interface affects the behavior of VGE. • Surface roughness down to Ra 0.25 μm within 3 min under optimized parameters. [ABSTRACT FROM AUTHOR]