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Dongzhou Jia

Other affiliations: Qingdao University
Bio: Dongzhou Jia is an academic researcher from Inner Mongolia University for Nationalities. The author has contributed to research in topics: Grinding & Lubrication. The author has an hindex of 22, co-authored 32 publications receiving 1503 citations. Previous affiliations of Dongzhou Jia include Qingdao University.

Papers
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Journal ArticleDOI
TL;DR: In this paper, the critical maximum undeformed equivalent chip thickness for ductile-brittle transition (DBhmax-e) of zirconia ceramics under different lubrication conditions was investigated.
Abstract: This study investigates the critical maximum undeformed equivalent chip thickness for ductile-brittle transition (DBhmax-e) of zirconia ceramics under different lubrication conditions. A DBhmax-e model is developed through geometry and kinematics analyses of ductile-mode grinding. Result shows that DBhmax-e decreases with increasing friction coefficient (μ). An experimental investigation is then conducted to validate the model and determine the effect of dry lubrication, minimum quantity lubrication (MQL), and nanoparticle jet minimum quantity lubrication (NJMQL) conditions on DBhmax-e. According to different formation mechanisms of debris, the grinding behavior of zirconia ceramics is categorized into elastic sliding friction, plastic removal, powder removal, and brittle removal. Grinding forces per unit undeformed chip thickness (Fn/h and Ft/h) are obtained. The lubrication condition affects the normal force and ultimately influences the resultant force on workpiece. In comparison with dry grinding (DBhmax-e = 0.8 μm), MQL and NJMQL grinding processes increase DBhmax-e by 0.99 and 1.79 μm respectively; this finding is similar to model result. The theoretical model is then assessed by different volume fractions of nanofluids under NJMQL condition with an average percentage error of less than 8.6%.

359 citations

Journal ArticleDOI
TL;DR: In this article, the dispersing mechanism of different surfactants and evaluated the dispersion stability and tribological performances of PPO-based CNT nanofluids were analyzed. And different experimental evaluations confirm that APE-10 is the optimal dispersant of CNT nanoparticles.

353 citations

Journal ArticleDOI
TL;DR: In this paper, a surface grinding experiment was conducted under three lubricating conditions (cryogenic air, minimum quantity lubrication, and cryogenic air nanofluids minimum quantity lubrication) with Ti 6Al 4V as the workpiece material.

300 citations

Journal ArticleDOI
TL;DR: In this article, a minimum chip thickness (h min ) model that considers lubrication conditions (represented by frictional angle β ) is developed according to strain gradient, as well as geometry and kinematics analyses.

296 citations

Journal ArticleDOI
TL;DR: In this paper, an improved theoretical force model that considers material removal and stacking mechanisms is presented. But the combined effect of material removal, stacking, and plastic stacking on surface grinding force model has not been investigated.
Abstract: Numerous researchers have developed theoretical and experimental approaches to force prediction in surface grinding under dry conditions. Nevertheless, the combined effect of material removal and plastic stacking on grinding force model has not been investigated. In addition, predominant lubricating conditions, such as flood, minimum quantity lubrication, and nanofluid minimum quantity lubrication, have not been considered in existing force models. This work presents an improved theoretical force model that considers material-removal and plastic-stacking mechanisms. Grain states, including cutting and ploughing, are determined by cutting efficiency (β). The influence of lubricating conditions is also considered in the proposed force model. Simulation is performed to obtain the cutting depth (ag) of each “dynamic active grain.” Parameter β is introduced to represent the plastic-stacking rate and determine the force algorithms of each grain. The aggregate force is derived through the synthesis of each single-grain force. Finally, pilot experiments are conducted to test the theoretical model. Findings show that the model's predictions are consistent with the experimental results, with average errors of 4.19% and 4.31% for the normal and tangential force components, respectively.

289 citations


Cited by
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Journal ArticleDOI
TL;DR: In this article, the dispersing mechanism of different surfactants and evaluated the dispersion stability and tribological performances of PPO-based CNT nanofluids were analyzed. And different experimental evaluations confirm that APE-10 is the optimal dispersant of CNT nanoparticles.

353 citations

Journal ArticleDOI
TL;DR: In this article, a high-temperature nickel-based alloy GH4169 was used as workpiece to evaluate the lubrication performance at the grinding wheel/workpiece interface, and the mechanism of lubrication was also studied based on the molecular structure of vegetable oil.

322 citations

Journal ArticleDOI
TL;DR: In this paper, the authors seek the attention of young scholars and experts working in the field of heat transfer by discussing the applications and challenges of hybrid nanofluids with a concise discussion on its history, synthesis techniques, thermophysical properties, research gaps, future directions, current status, and the leading groups, organizations and countries around the world.

312 citations

Journal ArticleDOI
TL;DR: In this paper, a surface grinding experiment was conducted under three lubricating conditions (cryogenic air, minimum quantity lubrication, and cryogenic air nanofluids minimum quantity lubrication) with Ti 6Al 4V as the workpiece material.

300 citations

Journal ArticleDOI
TL;DR: In this article, a minimum chip thickness (h min ) model that considers lubrication conditions (represented by frictional angle β ) is developed according to strain gradient, as well as geometry and kinematics analyses.

296 citations