Lubrication performance of rapeseed oil-based nano-lubricants in parallel tubular channel angular pressing process

Due to the biological risks of using the conventional lubricants,the vegetable oils have been considered nowadays.Besides,to improve the tribological properties of the vegetable oils in various applications like metal forming processes,nanoparticles have been used as additives.This research evaluated the lubrication performance of the Al2O3 and TiO2 nanoparticles dispersed in rapeseed oil during the parallel tubular channel angular pressing (PTCAP) process.The experimental PTCAP tests have been fulfilled under three lubrication conditions and the comparison between the PTCAP processed tubes has been performed in terms of the maximum forming force,surface roughness,and microhardness.The experimental results indicate that adding the mentioned nanoparticles has caused at least a 50% reduction in the maximum deformation load.Moreover,a remarkable decrement in the surface roughness of the formed tubes has been obtained.

The Effect and Mechanism of Nano-Cu Lubricating Additives on the Electroless Deposited Ni-W-P Coating

The coating and deposition process with excellent anti wear and suitable for industrial application were developed, and the optimum bath composition and process were obtained by studying the influence of the bath composition, temperature and pH value on the deposition rate and the plating solution stability. Moreover, the tribological properties of nano-Cu lubricating additives and electroless deposited Ni-W-P coating as well as their synergistic effect are researched using ring-block abrasion testing machine and energy dispersive spectrometer. Research results show that Ni-W-P alloy coating and nano-Cu lubricating additive have excellent synergistic effect, e g, the wear resistance of Ni-W-P alloy coating （with heat treatment and the oil with nano-Cu additives） has increased hundreds times than 45 steel as the metal substrate with the basic oil, and zero wear is achieved, which breaks through the bottleneck of previous separate research of the above-mentioned two aspects.

Mechanical behavior and semiempirical force model of aerospace aluminum alloy milling using nano biological lubricant

Aerospace aluminum alloy is the most used structural material for rockets,aircraft,spacecraft,and space stations.The deterioration of surface integrity of dry machining and the insufficient heat transfer capacity of minimal quantity lubrication have become the bottleneck of lubrication and heat dissipation of aerospace aluminum alloy.However,the excellent thermal conductivity and tribological properties of nanofluids are expected to fill this gap.The traditional milling force models are mainly based on empirical models and finite element simulations,which are insufficient to guide industrial manufacturing.In this study,the milling force of the integral end milling cutter is deduced by force analysis of the milling cutter element and numerical simulation.The instantaneous milling force model of the integral end milling cutter is established under the condition of dry and nanofluid minimal quantity lubrication(NMQL)based on the dual mechanism of the shear effect on the rake face of the milling cutter and the plow cutting effect on the flank surface.A single factor experiment is designed to introduce NMQL and the milling feed factor into the instantaneous milling force coefficient.The average absolute errors in the prediction of milling forces for the NMQL are 13.3%,2.3%,and 7.6%in the x-,y-,and z-direction,respectively.Compared with the milling forces obtained by dry milling,those by NMQL decrease by 21.4%,17.7%,and 18.5%in the x-,y-,and z-direction,respectively.

3D radiative convective flow of ZnO-SAE50nano-lubricant in presence of varying magnetic field and heterogeneous reactions

A numerical simulation is presented to investigate the effect of an exponentially varying magnetic field on three dimensional flow of Zinc Oxide-Society of Automotive Engineers 50 nanolubricant(ZnO-SAE50nano-lubricant)past a stretching sheet.Subsequently the impact of homogenous and heterogeneous reactions on the flow of nanolubricant concerned has also taken into account.The study has been strengthened by introducing the convection mechanism and the effect of thermal radiation.Similarity transformations are employed to transform the set of partial governing equations into the set of ordinary differential equations.The suitable boundary conditions are used to obtain the numerical solution.The numerical results are simulated using Matlab bvp4c solver and validated with the existing results.The flow characteristics,thermal characteristics,nanoparticle concentration and some non-dimensional numbers are computed under the influence of the pertinent parameters.The valuable outcome of the current study is that augmented magnetic field strength is the root cause of diminishing axial as well as transverse velocities and growing trend of fluid temperature.Also,the coeffi-cients of homogenous and heterogeneous reactions are boons for ascending concentration boundary layer.