Qingdao Technological University

About: Qingdao Technological University is a education organization based out in Qingdao, China. It is known for research contribution in the topics: Lubrication & Grinding. The organization has 2461 authors who have published 2200 publications receiving 21608 citations.

Some new triazole derivatives as inhibitors for mild steel corrosion in acidic medium

Abstract: Two triazole derivatives, 3,4-dichloro-acetophenone-O-1'-(1',3',4'-triazolyl)-methaneoxime (4-DTM) and 2,5-dichloro-acetophenone-O-1'-(1',3',4'-triazolyl)-methaneoxime (5-DTM) were synthesized, and the inhibition effects for mild steel in 1 M HCl solutions were investigated by weight loss measurements, electrochemical tests and scanning electronic microscopy (SEM). The weight loss measurements showed that these compounds have excellent inhibiting effect at a concentration of 1.0 x 10(-3) M. The potentiodynamic polarization experiment revealed that the triazole derivatives are inhibitors of mixed-type and electrochemical impedance spectroscopy (EIS) confirmed that changes in the impedance parameters (R-ct and C-dl) are due to surface adsorption. The inhibition efficiencies obtained from weight loss measurements and electrochemical tests were in good agreement. Adsorption followed the Langmuir isotherm with negative values of the free energy of adsorption Delta G(ads)(o). The thermodynamic parameters of adsorption were determined and are discussed. Results show that both 4-DTM and 5-DTM are good inhibitors for mild steel in acid media.

Experimental Evaluation of the Lubrication Performance of MoS2/CNT Nanofluid for Minimal Quantity Lubrication in Ni-based Alloy Grinding

Abstract: A nanofluid minimum quantity lubrication with addition of one kind of nanoparticle has several limitations, such as grinding of difficult-to-cutting materials Hybrid nanoparticles integrate the properties of two or more kinds of nanoparticles, thus having better lubrication and heat transfer performances than single nanoparticle additives However, the use of hybrid nanoparticles in nanofluid minimum quantity lubrication grinding has not been reported This study aims to determine whether hybrid nanoparticles have better lubrication performance than pure nanoparticle A hybrid nanofluid consisting of MoS2 nanoparticles with good lubrication effect and CNTs with high heat conductivity coefficient is investigated The effects of the hybrid nanofluid on grinding force, coefficient of friction, and workpiece surface quality for Ni-based alloy grinding are analyzed Results show that the MoS2/CNT hybrid nanoparticles achieve better lubrication effect than single nanoparticles The optimal MoS2/CNT mixing ratio and nanofluid concentration are 2:1 and 6 wt%, respectively