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This paper investigates the applicability of a new constitutive model with acoustoplasticity (CMA) to characterise the material deformation at ultra-high strain rates. It shows that this constitutive model enables the predictions of the material softening effect under high frequency impacts. Both the finite element analysis incorporating the CMA and experimental validations have been conducted with a specifically designed ultrasonic vibrator that can generate high frequency impacts. The study concludes that the CMA can reliably capture the material deformation responses to ultra-high strain rates and that it is applicable to problems when acoustoplasticity becomes important.
Liangchi Zhang; Chuhan Wu; Hossein Sedaghat. A note on the applicability of a constitutive model with acoustoplasticity to high strain rate deformation induced by high frequency impacts. International Journal of Impact Engineering 2021, 157, 103977 .
AMA StyleLiangchi Zhang, Chuhan Wu, Hossein Sedaghat. A note on the applicability of a constitutive model with acoustoplasticity to high strain rate deformation induced by high frequency impacts. International Journal of Impact Engineering. 2021; 157 ():103977.
Chicago/Turabian StyleLiangchi Zhang; Chuhan Wu; Hossein Sedaghat. 2021. "A note on the applicability of a constitutive model with acoustoplasticity to high strain rate deformation induced by high frequency impacts." International Journal of Impact Engineering 157, no. : 103977.
Potassium dihydrogen phosphate (KDP) crystals are important materials in high-energy laser systems. However, because these crystals are brittle and soft, machining-induced defects often emerge in KDP components. This study aimed to investigate the material removal mechanisms and characteristics of KDP during nanoscratching using Berkovich, spherical, and conical indenters. We found that KDP surface layers could be removed in a ductile mode at the micro/nanoscale and that dislocation motion was one of the main removal mechanisms. Removal characteristics are related to the stress fields generated by indenter geometries. The spherical indenter achieved a ductile removal mode more easily. The lateral force of nanoscratching increased with an increase in the normal force. The coefficient of friction (COF) followed the same trend as the lateral force when spherical and conical indenters were used. However, the COF was independent of the normal force when using a Berkovich indenter. We found that these COF variations could be accurately described by friction models.
Ning Hou; Yong Zhang; Liang-Chi Zhang; Ming-Hai Wang. Material removal mechanisms and characteristics of potassium dihydrogen phosphate crystals under nanoscratching. Advances in Manufacturing 2021, 1 -10.
AMA StyleNing Hou, Yong Zhang, Liang-Chi Zhang, Ming-Hai Wang. Material removal mechanisms and characteristics of potassium dihydrogen phosphate crystals under nanoscratching. Advances in Manufacturing. 2021; ():1-10.
Chicago/Turabian StyleNing Hou; Yong Zhang; Liang-Chi Zhang; Ming-Hai Wang. 2021. "Material removal mechanisms and characteristics of potassium dihydrogen phosphate crystals under nanoscratching." Advances in Manufacturing , no. : 1-10.
Being an important nonlinear optical material, potassium dihydrogen phosphate (KDP) has been widely used in many technological fields such as laser frequency conversion and high-speed Q-switching. Nevertheless, KDP is one of the most difficult-to-handle materials because it is prone to phase transformations under mechanical loading during component fabrication. This study investigated the mechanisms of phase transformations and microstructural lattice slipping in KDP with the aid of molecular dynamics (MD) analysis. A fundamental structural characterization method was established to identify the structural changes, enabling the determination of the corresponding trigger criteria. The results showed that various phase transformations can be initiated under a range of mechanical loading conditions. Microstructural lattice slipping can be nucleated via different mechanisms. These findings provide insights for developing damage-free manufacturing processes of ultraprecision KDP components.
Shengyao Yang; Liangchi Zhang; ZhongHuai Wu. Characterization and criteria of phase transformations and lattice slipping in potassium dihydrogen phosphate crystals. Journal of the American Ceramic Society 2021, 1 .
AMA StyleShengyao Yang, Liangchi Zhang, ZhongHuai Wu. Characterization and criteria of phase transformations and lattice slipping in potassium dihydrogen phosphate crystals. Journal of the American Ceramic Society. 2021; ():1.
Chicago/Turabian StyleShengyao Yang; Liangchi Zhang; ZhongHuai Wu. 2021. "Characterization and criteria of phase transformations and lattice slipping in potassium dihydrogen phosphate crystals." Journal of the American Ceramic Society , no. : 1.
In a deep drawing process, the contact sliding between the surfaces of a metal sheet and a die/mold under high contact stresses brings about wear of both the counterpart surfaces. This paper aims to investigate the influence of tool and workpiece properties on the wear behaviors subjected to cylinder-on-flat sliding conditions. The effects of different tool materials (Cr12MoV, SKD11, and DC53), radii, surface hardness, and surface treatment processes including thermal diffusion (TD) coating, nitriding coating, and vacuum heat treatment (VHT) were investigated. Two types of workpieces with high tensile strength (DP980 and QP980) were also applied in the tests. The friction coefficient, surface morphology, and material removal were analyzed with the aid of load cells installed and microscopy measurements. It was found that the DC53 tool experiences the smallest tool wear and material transfer. The least material transfer is attributed to its low adhesion to workpiece material, which also results in more wear debris and a higher friction coefficient. The TD coated tool surface can further improve the wear resistance and bring about the lowest friction coefficient. The debris density associated with the TD coating is also the smallest. These findings provide a useful guideline for the design and optimization of molds/dies for the deep drawing processes of sheet metals.
Wei Li; Liangchi Zhang; Chuhan Wu; Zhenxiang Cui; Chao Niu. Influence of Tool and Workpiece Properties on the Wear of the Counterparts in Contact Sliding. Journal of Tribology 2021, 144, 1 .
AMA StyleWei Li, Liangchi Zhang, Chuhan Wu, Zhenxiang Cui, Chao Niu. Influence of Tool and Workpiece Properties on the Wear of the Counterparts in Contact Sliding. Journal of Tribology. 2021; 144 (2):1.
Chicago/Turabian StyleWei Li; Liangchi Zhang; Chuhan Wu; Zhenxiang Cui; Chao Niu. 2021. "Influence of Tool and Workpiece Properties on the Wear of the Counterparts in Contact Sliding." Journal of Tribology 144, no. 2: 1.
This paper presents a comprehensive investigation on the incremental sheet metal forming assisted by ultrasonic vibration (UV). With the aid of a new acoustoplasticity constitutive model which can accurately capture the deformation response to ultra-high strain rates, extensive numerical analyses on incremental sheet metal forming under UV were conducted by using the finite element method. Corresponding experimental investigations were also carried out to examine the capacity of the constitutive and numerical models. The effects of critical parameters, such as tool size, tool revolution speed, feed rate, pitch and tool vibration amplitude, on the forming force, maximum sheet thickness reduction and springback, were investigated in detail. It was found that the models can realistically predict the incremental sheet metal forming under UV. It is expected that this research can facilitate the development of ultrasonic vibration–assisted forming techniques.
Liangchi Zhang; Chuhan Wu; Hossein Sedaghat. Ultrasonic vibration–assisted incremental sheet metal forming. The International Journal of Advanced Manufacturing Technology 2021, 114, 3311 -3323.
AMA StyleLiangchi Zhang, Chuhan Wu, Hossein Sedaghat. Ultrasonic vibration–assisted incremental sheet metal forming. The International Journal of Advanced Manufacturing Technology. 2021; 114 (11-12):3311-3323.
Chicago/Turabian StyleLiangchi Zhang; Chuhan Wu; Hossein Sedaghat. 2021. "Ultrasonic vibration–assisted incremental sheet metal forming." The International Journal of Advanced Manufacturing Technology 114, no. 11-12: 3311-3323.
The effect of amorphous film on the deformation mechanism and mechanical properties of 6H-SiC were systematically explored by a combination of both experiments and molecular dynamic (MD) simulations in nanoindentation. The experimental results showed that the plastic deformation of surface-modified 6H-SiC is mainly accommodated by dislocation activities in the subsurface and an amorphous layer with uniform thickness. The MD results indicated that the amorphous layer on the surface of the residual indentation mark consists of both amorphous SiO2 and SiC due to direct amorphization. In addition, the amorphous SiO2 film undergoes densification and then ruptures with the indentation depth increases. The modulus and hardness increase with increasing the indentation depth at the initial stage but will reach their stable values equivalent to monocrystalline 6H-SiC.
ZhongHuai Wu; Liangchi Zhang. Mechanical properties and deformation mechanisms of surface-modified 6H-silicon carbide. Journal of Materials Science & Technology 2021, 90, 58 -65.
AMA StyleZhongHuai Wu, Liangchi Zhang. Mechanical properties and deformation mechanisms of surface-modified 6H-silicon carbide. Journal of Materials Science & Technology. 2021; 90 ():58-65.
Chicago/Turabian StyleZhongHuai Wu; Liangchi Zhang. 2021. "Mechanical properties and deformation mechanisms of surface-modified 6H-silicon carbide." Journal of Materials Science & Technology 90, no. : 58-65.
This paper presents a three-dimensional kinematic simulation of surface topography ground by a D301 electroplated diamond wheel. For an individual cubo-octahedron diamond grain, its cutting process is modeled by decomposing it into active grain edges and discrete cutting points. By successively integrating the material removal caused by all the grains, the ground surface topography of workpiece is successfully predicted. The predicted surface roughness is close to the theoretical and experimental values with relative errors of − 7.9% and − 3.3% for aluminum and fused silica, respectively. The study reveals that the other amplitude parameters, e.g., kurtosis and skewness, of surface profiles can reflect the material removal mechanisms. The lateral pile-up of plastic aluminum alloy in grinding increases the kurtosis while the fracture of brittle fused silica results in a prominently negative skewness. For a fresh grinding wheel, the surface roughness Ra reaches a plateau after a rapid increase as the grinding depth increases to 1.25 times the SD of the grain protrusion heights. By contrast, the effects of grinding depth on the surface topography are negligible when the wear depth is beyond a certain value. As the feed rate increases, the number of active abrasive grains gradually increases. Meanwhile, the effect of the grain circumferential distribution on the workpiece surface topography becomes significant.
Changsheng Li; Liangchi Zhang; Jianjun Ding; Chuhan Wu; Lin Sun; Qijing Lin; Zhuangde Jiang. Kinematic modeling of surface topography ground by an electroplated diamond wheel. The International Journal of Advanced Manufacturing Technology 2021, 114, 2753 -2765.
AMA StyleChangsheng Li, Liangchi Zhang, Jianjun Ding, Chuhan Wu, Lin Sun, Qijing Lin, Zhuangde Jiang. Kinematic modeling of surface topography ground by an electroplated diamond wheel. The International Journal of Advanced Manufacturing Technology. 2021; 114 (9-10):2753-2765.
Chicago/Turabian StyleChangsheng Li; Liangchi Zhang; Jianjun Ding; Chuhan Wu; Lin Sun; Qijing Lin; Zhuangde Jiang. 2021. "Kinematic modeling of surface topography ground by an electroplated diamond wheel." The International Journal of Advanced Manufacturing Technology 114, no. 9-10: 2753-2765.
This paper presents a novel three-dimensional characterisation of the wear effects of a roll surface on the texture transfer in skin-pass rolling. The method integrates the interactions of the microscale elastic deformation of roll surface asperities with the microscale plastic deformation of strip surface asperities. An elasticity theory and a discrete fast Fourier transform were used to rationally predict the microscale elastic deformation of work roll in the rolling system. The microscale plastic deformation of the asperities on the soft strip surface was calculated by the material redistribution process. The Archard wear law was used to consider the wear effects with the random contact pressure, relative sliding and surface hardness. A multiscale analysis was carried out by the dynamic explicit finite element method (FEM), which fully coupled microscale surface contacts, macroscale elastic deformation of the work roll and the bulk plastic deformation of the metal strip. Due to the complexity associated with numerical simulation, a novel modularised approach was established to complete the calculation in a feasible and efficient manner. The study reveals that the roughness scale of a rolled metal strip decreases gradually due to the roll surface wear and that the rolling force, relative sliding and rolling speed at the roll-strip interface significantly affect the roll surface wear. It is expected that the method established can be used to control the surface texture transfer in skin-pass rolling under the continuous wear of roll surfaces.
Chuhan Wu; Liangchi Zhang; Peilei Qu; Shanqing Li; Zhenglian Jiang; Wei Li. Surface texture transfer in skin-pass rolling with the effect of roll surface wear. Wear 2021, 203764 .
AMA StyleChuhan Wu, Liangchi Zhang, Peilei Qu, Shanqing Li, Zhenglian Jiang, Wei Li. Surface texture transfer in skin-pass rolling with the effect of roll surface wear. Wear. 2021; ():203764.
Chicago/Turabian StyleChuhan Wu; Liangchi Zhang; Peilei Qu; Shanqing Li; Zhenglian Jiang; Wei Li. 2021. "Surface texture transfer in skin-pass rolling with the effect of roll surface wear." Wear , no. : 203764.
This paper investigates the surface texture transfer mechanisms in lubricated skin-pass-rolling of metal strips with three-dimensional rough surfaces of both regular patterns and random surface asperity distributions. Two important steps have been completed. The first is the successful establishment of an efficient numerical method for predicting the 3D texture transfer. It was identified that the new method can be used reliably with the key complex factors coupled in skin-pass-rolling, such as the effects of lubricant and surface roughness. The second is the exploration of the texture transfer mechanisms with the aid of this new method. In addition, the effects of hydrodynamic pressure on the texture transfer efficiency were comprehensively investigated by a dynamic explicit finite element analysis. It was found that lubrication plays a critical role in determining the surface texture transfer. The texture transfer ratio decreases with increasing the lubricant viscosity. A larger pressure coefficient brings about a lower texture transfer ratio; but a larger reduction ratio leads to a greater texture transfer.
Chuhan Wu; Liangchi Zhang; Peilei Qu; Shanqing Li; Zhenglian Jiang; Wei Li. An investigation into the texture transfer in the process of lubricated skin pass rolling. Journal of Manufacturing Science and Engineering 2021, 1 -44.
AMA StyleChuhan Wu, Liangchi Zhang, Peilei Qu, Shanqing Li, Zhenglian Jiang, Wei Li. An investigation into the texture transfer in the process of lubricated skin pass rolling. Journal of Manufacturing Science and Engineering. 2021; ():1-44.
Chicago/Turabian StyleChuhan Wu; Liangchi Zhang; Peilei Qu; Shanqing Li; Zhenglian Jiang; Wei Li. 2021. "An investigation into the texture transfer in the process of lubricated skin pass rolling." Journal of Manufacturing Science and Engineering , no. : 1-44.
Potassium dihydrogen phosphate (KDP) is an important material to a range of technological fields owing to its unique optical and physical properties, such as its frequency-doubling, high efficiency in nonlinear conversion and excellent photoelectric and piezoelectric capabilities. However, the basic mechanical constants of this material have never been accurately determined, and its failure mechanisms, too, have not been properly revealed. This paper aims to determine precisely the complete set of mechanical constants of KDP and investigate its failure mechanisms when the material is subjected to a variety of loading conditions. It was identified that the 6 independent mechanical constants C11, C33, C12, C13, C44 and C66 of KDP are 50.36, 50.67, −4.08, 12.58, 9.99 and 2.84 GPa, respectively; its Poisson's ratio ν is 0.24, its bulk modulus K and shear modulus G are 21.17 and 13.27 GPa, respectively; and its elastic moduli in the and directions, E100 and E001, are 46.14 and 43.83 GPa, respectively. It was found that the atomic structure of KDP greatly influences its anisotropy and leads to distinguished failure mechanisms in different lattice orientations. A perfect KDP crystal fails under the stress of 3.19 GPa at the strain of 10% in the / direction and 1.69 GPa at the strain of 5% in the direction. It was also found that the deformation of KDP under a uniaxial or a biaxial strain is due to the rotation of the tetrahedron PO4 groups.
Shengyao Yang; Liangchi Zhang. Characterization of mechanical properties and failure of potassium dihydrogen phosphate under mechanical stressing. Ceramics International 2021, 47, 15875 -15882.
AMA StyleShengyao Yang, Liangchi Zhang. Characterization of mechanical properties and failure of potassium dihydrogen phosphate under mechanical stressing. Ceramics International. 2021; 47 (11):15875-15882.
Chicago/Turabian StyleShengyao Yang; Liangchi Zhang. 2021. "Characterization of mechanical properties and failure of potassium dihydrogen phosphate under mechanical stressing." Ceramics International 47, no. 11: 15875-15882.
This paper investigates the surface texture transfer with elastically deformed work rolls in skin-pass rolling. A numerical approach was developed to efficiently overcome the multiscale challenges associated with the numerical characterisations. To couple the microscale plastic deformation of strip surface asperities with the microscale elastic deformation of roll surface asperities, a specific method was first developed to generate the characteristics between normal contact pressure and interface separation. To deal with the three-dimensional deterministic rough surfaces, a material redistribution scheme was used to predict the plastic deformation of the strip surface asperities and a discrete fast Fourier transform algorithm was employed to efficiently calculate the elastic deflection of the roll surface asperities. These enabled the subsequent multiscale analysis in coupling the microscale interface contact with the macroscale deformation of the metal strip and work roll. As such, the stick/slip transition in the rolling bite due to the elastic deformation of the roll as well as the surface topography of the rolled strip have been quantified. The new method has successfully revealed the effects of elastic roll deformation, roll radius, and strip thickness/roughness on the resultant surface texture of strips in skin-pass rolling.
Chuhan Wu; Liangchi Zhang; Peilei Qu; Shanqing Li; Zhenglian Jiang. Effect of the elastic deformation of rolls on the surface texture transfer in skin-pass rolling. International Journal of Mechanical Sciences 2021, 198, 106358 .
AMA StyleChuhan Wu, Liangchi Zhang, Peilei Qu, Shanqing Li, Zhenglian Jiang. Effect of the elastic deformation of rolls on the surface texture transfer in skin-pass rolling. International Journal of Mechanical Sciences. 2021; 198 ():106358.
Chicago/Turabian StyleChuhan Wu; Liangchi Zhang; Peilei Qu; Shanqing Li; Zhenglian Jiang. 2021. "Effect of the elastic deformation of rolls on the surface texture transfer in skin-pass rolling." International Journal of Mechanical Sciences 198, no. : 106358.
Magnesium alloy AZ31B is an important lightweight, high specific strength material for new generations of energy-effective vehicles. Presently, a critical challenge that the vehicle production is facing is how to prevent the material from surface oxidation at elevated temperatures. This paper aims to investigate the effect of thermal oxidation and chemical compositions of oxides on the wear of AZ31B. The tribology experiments were conducted by a contact pair of pin-on-disc under elevated temperatures. The disc and pin were made by AZ31B and the production tooling steel 86CrMoV7, respectively. The composition and morphology of the disc surface were examined by the scanning electron microscope (SEM). It was found that the initial surface oxide film naturally formed prior to testing at room temperature (RT) was thin, compact and protective. However, the film would lose its protection capability when the temperature rose because of the thickened film layer and the emergence of the oxide nodules. At a higher temperature, the oxide nodules grew more quickly. Besides, more oxide nodules emerged, and the film started to crack as the temperature increased, leading to a higher wear rate. The friction coefficient varied at different temperatures due to the change in the dominant wear mechanism of AZ31B. The minimum wear rate was found to occur at 200 °C and the maximum at 400 °C. It was also found that the surface hardness of AZ31B decreased from 75 HV2 at 25 °C to 50 HV2 at 200 °C, and then fluctuated around 50 HV2 at higher temperatures, which further accelerated the wear process.
Yan Wang; Chuhan Wu; Liangchi Zhang; Peilei Qu; Shanqing Li; Zhenglian Jiang. Thermal oxidation and its effect on the wear of Mg alloy AZ31B. Wear 2021, 476, 203673 .
AMA StyleYan Wang, Chuhan Wu, Liangchi Zhang, Peilei Qu, Shanqing Li, Zhenglian Jiang. Thermal oxidation and its effect on the wear of Mg alloy AZ31B. Wear. 2021; 476 ():203673.
Chicago/Turabian StyleYan Wang; Chuhan Wu; Liangchi Zhang; Peilei Qu; Shanqing Li; Zhenglian Jiang. 2021. "Thermal oxidation and its effect on the wear of Mg alloy AZ31B." Wear 476, no. : 203673.
Monocrystalline 6H-silicon carbide is a promising material for advanced components and devices; but is also a difficult-to-machine material due to its hardness, brittleness and structural anisotropy. With the aid of large-scale molecular dynamics simulations, this paper comprehensively studied the structural anisotropy effect on the nanoscratching of 6H–SiC. Six typical combinations of scratching plane and direction were selected, namely, (0001), (0001), (112‾0), (112‾0), (11‾00) and (11‾00). It was found that the scratching-induced deformation morphology, activated dislocations and scratching forces varied significantly under different combinations of scratching conditions due to the strong anisotropy effect of the material. By evaluating the actual depth of cut, elastic recovery, surface roughness and maximum subsurface damage depth, basal plane (0001) along direction was identified as the best combination for conducting nanoscratching on 6H–SiC. Corresponding high-resolution TEM results show that the mechanism revealed by the MD analysis reflects the true deformation of the material.
ZhongHuai Wu; Liangchi Zhang; Weidong Liu. Structural anisotropy effect on the nanoscratching of monocrystalline 6H-silicon carbide. Wear 2021, 203677 .
AMA StyleZhongHuai Wu, Liangchi Zhang, Weidong Liu. Structural anisotropy effect on the nanoscratching of monocrystalline 6H-silicon carbide. Wear. 2021; ():203677.
Chicago/Turabian StyleZhongHuai Wu; Liangchi Zhang; Weidong Liu. 2021. "Structural anisotropy effect on the nanoscratching of monocrystalline 6H-silicon carbide." Wear , no. : 203677.
Potassium dihydrogen phosphate (KDP) is an important material in the optics industry due to its excellent physical and optical properties. It is also a difficult-to-process material due to its brittleness and sensitivity to environment and external stresses such as contact sliding stresses, temperature variation and humidity change. This paper presents the first investigation into the nano-abrasion wear mechanisms of KDP using molecular dynamics (MD) analysis. Nanoscratching simulations were conducted with various scratching depths in various crystallographic orientations. It was found that the deformation mechanisms of KDP under nano-abrasion are greatly affected by the anisotropy of the material. The nano-abrasion on the (001) surface experiences the least resistance of material removal. The elastic recovery on the (100) surface is greater than that on the (001) surface. The coefficient of friction increases with increasing the scratching depth, and reaches the highest on the (001) surface. Different phase transformations emerge under contact stresses. The study revealed that the phase transformations are initiated under corresponding critical hydrostatic stresses with high shear stress.
Shengyao Yang; Liangchi Zhang; ZhongHuai Wu. An investigation on the nano-abrasion wear mechanisms of KDP crystals. Wear 2021, 476, 203692 .
AMA StyleShengyao Yang, Liangchi Zhang, ZhongHuai Wu. An investigation on the nano-abrasion wear mechanisms of KDP crystals. Wear. 2021; 476 ():203692.
Chicago/Turabian StyleShengyao Yang; Liangchi Zhang; ZhongHuai Wu. 2021. "An investigation on the nano-abrasion wear mechanisms of KDP crystals." Wear 476, no. : 203692.
This paper investigates the friction, wear and deformation of potassium dihydrogen phosphate (KDP) using the nano-scratching technique with both Berkovich and conical indenters. It was found that the indenter tip radius significantly affected the tribological properties of the material. Under a smaller tip radius (Berkovich indenter), the pill-ups were higher at the end of the wear/scratching tracks and friction fluctuation during nano-scratching was greater. The ploughing and brittle deformation dominated the wear mode under a larger tip radius (conical indenter). The KDP deformed in a ductile, ploughing or ploughing and brittle mode depending on the magnitude of the scratching load. The variation in friction coefficient was related to the wear mode and brittle deformation brought about a greater friction fluctuation. The crystal orientation (plane) also affected the behaviour of friction and wear of the material. The softer plane of KDP experienced more brittle deformation under both indenter types. The indenter tip radius had a significant influence on the surface morphology of KDP.
M.L. Rahaman; Liangchi Zhang. An investigation on the friction, wear and deformation of potassium dihydrogen phosphate. Wear 2021, 203624 .
AMA StyleM.L. Rahaman, Liangchi Zhang. An investigation on the friction, wear and deformation of potassium dihydrogen phosphate. Wear. 2021; ():203624.
Chicago/Turabian StyleM.L. Rahaman; Liangchi Zhang. 2021. "An investigation on the friction, wear and deformation of potassium dihydrogen phosphate." Wear , no. : 203624.
This paper provides a comprehensive review on the multiscale characterisation of interface stresses in cold rolling considering both the random asperity deformation and lubrication. The characterisation of the microscopic interface friction was analysed with the effects of lubricant shearing, asperity sliding, lubricant additives and oil-in-water emulsion. Multiscale modelling of rolling under different lubrication regimes was discussed in detail. Some open problems for further studies were also summarised.
Chuhan Wu; Liangchi Zhang; Peilei Qu; Shanqing Li; Zhenglian Jiang. Multiscale Interface Stress Characterisation in Cold Rolling. Metals and Materials International 2021, 1 -17.
AMA StyleChuhan Wu, Liangchi Zhang, Peilei Qu, Shanqing Li, Zhenglian Jiang. Multiscale Interface Stress Characterisation in Cold Rolling. Metals and Materials International. 2021; ():1-17.
Chicago/Turabian StyleChuhan Wu; Liangchi Zhang; Peilei Qu; Shanqing Li; Zhenglian Jiang. 2021. "Multiscale Interface Stress Characterisation in Cold Rolling." Metals and Materials International , no. : 1-17.
This paper presents an artificial intelligence (AI) method for the evolution prediction of surface scratching in sheet metals subjected to contact sliding. Ball-on-disk sliding was employed, and ball diameter, normal load, surface roughness, sliding cycles and the maximum scratching depth in the metal sheet were taken as the fuzzy variables to assess the contributions of individual variables to the surface damage. To improve the prediction accuracy, the quantum-behaved particle swarm optimisation (QPSO) algorithm was further developed and utilised to refine the fuzzy model by optimising the membership functions of the fuzzy variables. It was found that this AI technique, which integrates the fuzzy set theory with the improved QPSO algorithm, can accurately, reliably and efficiently predict the surface scratching evolution, which is otherwise impossible to be implemented.
Wei Li; Liangchi Zhang; Xinping Chen; Chuhan Wu; Zhenxiang Cui; Chao Niu. Predicting the evolution of sheet metal surface scratching by the technique of artificial intelligence. The International Journal of Advanced Manufacturing Technology 2020, 112, 853 -865.
AMA StyleWei Li, Liangchi Zhang, Xinping Chen, Chuhan Wu, Zhenxiang Cui, Chao Niu. Predicting the evolution of sheet metal surface scratching by the technique of artificial intelligence. The International Journal of Advanced Manufacturing Technology. 2020; 112 (3-4):853-865.
Chicago/Turabian StyleWei Li; Liangchi Zhang; Xinping Chen; Chuhan Wu; Zhenxiang Cui; Chao Niu. 2020. "Predicting the evolution of sheet metal surface scratching by the technique of artificial intelligence." The International Journal of Advanced Manufacturing Technology 112, no. 3-4: 853-865.
This paper describes the wear behavior, subsurface damage mechanism with structural change and indentation creep of bioinert Ti–6Al–4V alloy at different applied loads. Wear test was carried out on a pin-on-disk tribometer and their subsurface damage and deformation mechanism induced by a dry contact sliding were examined by SEM, EBSD and TEM techniques. A microstructural analysis revealed that a very fine β-Ti phase is evenly distributed in the α-Ti matrix. Consequently, the elastic modulus and microhardness of the alloy displayed 107.3 GPa and 324 HV, respectively at room temperature. However, the elastic modulus of Ti-alloy dropped approximately 35.4% at 700 °C. On the other hand, during the pin-on-disk test, severe loose fragments and delamination or plunged groove were observed at the edge of the overall wear tracks, causing abrasive wear. Under a low load, microcracks appeared beneath at the wear track. As increasing the load, the gross plastic deformation and severe microcracks emerged at the worn surface and soften the matrix due to frictional heat, leading to an accelerated wear rate. However, at the worn subsurface recrystallisation phenomena occurred. The grain size reduced and the nanohardness and elastic properties increased.
Asit Kumar Gain; Liangchi Zhang; Sean Lim. Tribological behavior of Ti–6Al–4V alloy: Subsurface structure, damage mechanism and mechanical properties. Wear 2020, 464-465, 203551 .
AMA StyleAsit Kumar Gain, Liangchi Zhang, Sean Lim. Tribological behavior of Ti–6Al–4V alloy: Subsurface structure, damage mechanism and mechanical properties. Wear. 2020; 464-465 ():203551.
Chicago/Turabian StyleAsit Kumar Gain; Liangchi Zhang; Sean Lim. 2020. "Tribological behavior of Ti–6Al–4V alloy: Subsurface structure, damage mechanism and mechanical properties." Wear 464-465, no. : 203551.
Potassium dihydrogen phosphate (KDP) is an important nonlinear optical material which plays a core role in electro-optic switches and laser spectroscopy. However, KDP is also one of the most difficult-to-handle materials due to its fragility, unstable microstructure and complex mechanical behaviour. Molecular dynamics (MD) simulation is an appropriate method to explore the deformation mechanisms of the material at the atomic scale. However, the challenge is that there is not a suitable potential function for describing the mechanical behaviour of KDP by using MD simulation. This paper successfully developed a potential function, which enables such insightful investigations. It was found that the established potential function can reliably predict the mechanical properties of KDP including its modulus in different crystal directions and structural changes under various loading conditions.
Shengyao Yang; Liangchi Zhang; Hongtao Xie; Weidong Liu. Interaction potential function for the deformation analysis of potassium dihydrogen phosphate using molecular dynamics simulation. Computational Materials Science 2020, 187, 110122 .
AMA StyleShengyao Yang, Liangchi Zhang, Hongtao Xie, Weidong Liu. Interaction potential function for the deformation analysis of potassium dihydrogen phosphate using molecular dynamics simulation. Computational Materials Science. 2020; 187 ():110122.
Chicago/Turabian StyleShengyao Yang; Liangchi Zhang; Hongtao Xie; Weidong Liu. 2020. "Interaction potential function for the deformation analysis of potassium dihydrogen phosphate using molecular dynamics simulation." Computational Materials Science 187, no. : 110122.
KDP single crystals are widely used in inertial confinement fusion and high power lasers due to the wide transmission band, high laser damage threshold, large nonlinear optical coefficient, etc. However, surface and subsurface damages are easily induced into the KDP crystal components during the machining process due to its high brittleness and distinct anisotropy. These damages will reduce the service accuracy and life of KDP crystal components. It is of great significance to study the brittle-to-ductile transition of KDP crystals to achieve high efficiency and precision machining of crystal components. In this work, a theoretical model of brittle-to-ductile transition load during the nanoindentation and nanoscratch processes of KDP crystals was established based on the energy conservation law and dislocation theory. This model took the anisotropy of KDP crystals into account. Nanoindentation and nanoscratch experiments by using different indenters were performed to verify the theoretical model of brittle-to-ductile transition load. The experimental results of the brittle-to-ductile transition load agreed well with the theoretical results, which indicated that the model was reliable. Both experimental and theoretical results showed that the critical load of brittle-to-ductile transition during the nanoindentation and nanoscratch processes increased as the half cone angle increased. In addition, the critical load of brittle-to-ductile transition load of the scratch was lower than that of the indentation under the same condition. The results also demonstrated that KDP crystals had distinct anisotropy during the nanoindentation and nanoscratch process. Brittle fracture was most likely to occur along [100] orientation during the scratch process. Under the same scratching condition, [110] orientation was prone to achieving ductile machining with high surface quality compared with other orientations.
Chen Li; Yong Zhang; Guangzhe Zhou; Zongjie Wei; Liangchi Zhang. Theoretical modelling of brittle-to-ductile transition load of KDP crystals on (001) plane during nanoindentation and nanoscratch tests. Journal of Materials Research and Technology 2020, 9, 14142 -14157.
AMA StyleChen Li, Yong Zhang, Guangzhe Zhou, Zongjie Wei, Liangchi Zhang. Theoretical modelling of brittle-to-ductile transition load of KDP crystals on (001) plane during nanoindentation and nanoscratch tests. Journal of Materials Research and Technology. 2020; 9 (6):14142-14157.
Chicago/Turabian StyleChen Li; Yong Zhang; Guangzhe Zhou; Zongjie Wei; Liangchi Zhang. 2020. "Theoretical modelling of brittle-to-ductile transition load of KDP crystals on (001) plane during nanoindentation and nanoscratch tests." Journal of Materials Research and Technology 9, no. 6: 14142-14157.