Developing of galling during the forming and its improvement by physical vapour depositing

Zhou, Luhai; Gao, Kaixiang; Zheng, Xiankun; Wang, Wurong; Wei, Xicheng; Hua, Meng

doi:10.1080/02670844.2017.1381375

Cited by 6 publications

(3 citation statements)

References 29 publications

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“…The surface quality was categorized into machined surface roughness (R a ), material deposition roughness (R b ) and machined cum deposition roughness (R ab ). Ra rises as the current increases because it produces more intense sparks [34], which create cracks and craters on the machined surface, lowering the quality of the machined surface. In the case of R b and R ab , the best surface quality was attained when machined at the current of 30 A, and with further increase worsens the surface quality owing to plasma densification.…”

Section: Resultsmentioning

confidence: 99%

Surface modification of Hastelloy processed by the Cu mixed electric discharge alloying technique

Jayachitra

Ranjith²,

Ramesh

et al. 2022

Surface Engineering

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An attempt was made in this study to coat Hastelloy with copper carbide utilizing an electric discharge alloying process. Experiments were carried out in such a way that materials were initially removed from the surface, but after a prescribed time in the absence of flushing, it was coated on the surface. Experiments were conducted by varying copper powder concentration, current, pulse on time, and gap distance and experimental runs were designed using the Taguchi mixed orthogonal array. Pure dielectric medium materials were removed from the surface, at 5 g l −1 PMEDM material removal followed by deposition occurred, beyond 10 g l −1 PMEDM condition, only material deposition was observed. Surface topography revealed that the cracks formed on the coated surface with an increase in Cu concentration get intensified and penetrated the base material. The hardness and wear resistance of coated samples are enhanced owing to the presence of harder carbide particles and mechanically mixed layer formation. The mode of wear was adhesive and abrasive for the uncoated and coated samples.

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Section: Resultsmentioning

confidence: 99%

Surface modification of Hastelloy processed by the Cu mixed electric discharge alloying technique

Jayachitra

Ranjith²,

Ramesh

et al. 2022

Surface Engineering

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“…During whole manufacturing process, the tool design has a significant role in the initiation of galling and it is highly vulnerable to the surface roughness of tool (without coating) rather than surface irregularities of the sheet [31]. Zhou et al [32], Yangui et al [33] and Dong et al [27] in this context researchers had reported that the commencement and progression of galling originates at the mould radius (i.e. around 0° to 70°) during forming process during which there is a severe plastic deformation of sheet metal, inducing adhesion of sheet material to the surface of the tool and hence galling occurs.…”

Section: Pothole In Design Of Sheet Metal Forming Contributing Gallingmentioning

confidence: 99%

A review: advancements in fluoro-based polymers for aggrandizing anti-galling and wear resistant characteristics

2019

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Galling is the surface phenomenon which involves adhesion of local contact points and creation of protrusions on the juxtaposition of surfaces owing to high friction, inappropriate tribological loading, starved lubrication and high contact pressure (~ 1000 kPa). All these factors result in severe plastic deformation varying from 8000 to 10,000 µε (ε-strain) and diffusion of materials into one another, which consequently results in fatigue wear, surface roughness, tribocorrosion and seizing up of critical parts. The aim of the review is to analyze and summarizes the issue of galling, concurrently it also deals with the novel and economical mitigation method i.e. use of fluorine based coatings e.g. PTFE, owing to their lowest friction coefficient from 0.02 to 0.2 among other solids, high stiffness, high thermal stability and non-adherent characteristics that augments the mechanical and tribological properties and concurrently protect against hostile environments that eventually upsurges the life of components.

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“…In order to be able to predict the value of coefficient of friction (COF) in analyses of sheet-forming processes, it is necessary to carry out the tribological test for a given pair of mating elements (tool and plate) [8]. The COF is mainly influenced by the roughness of the tool and of the material formed, lubrication conditions [9], mechanical properties of the sheet metal [10], character of contact (static/dynamic) [11] and temperature [12].…”

Section: Introductionmentioning

confidence: 99%

Effect of Lubricant Type on the Friction Behaviours and Surface Topography in Metal Forming of Ti-6Al-4V Titanium Alloy Sheets

et al. 2021

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The aim of the research described in this paper is to analyse the synergistic effect of types of synthetic oil and their density on the value of the coefficient of friction (COF) of Ti-6Al-4V titanium alloy sheets. Lubrication performance of commercial synthetic oils (machine, gear, engine and hydraulic) was tested in a strip draw friction test. The friction tests consisted of pulling a strip specimen between two cylindrical fixed countersamples. The countersamples were placed in the simulator base mounted on a uniaxial tensile test machine. Due to the complex synergistic effect of different strip drawing test parameters on the COF, artificial neural networks were used to find this relationship. In the case of both dry and lubricated conditions, a clear trend was found of a reduction of the coefficient of friction with nominal pressure. Engine oil 10W-40 was found to be the least favourable lubricant in reducing the coefficient of friction of Grade 5 titanium sheets. The two main tribological mechanisms, i.e., galling and ploughing, played the most important role in the friction process on the test sheets. In the range of nominal pressures considered, and with the synthetic oils tested, the most favourable lubrication conditions can be obtained by using a type of oil with a low viscosity index and a high kinematic viscosity.

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Developing of galling during the forming and its improvement by physical vapour depositing

Cited by 6 publications

References 29 publications

Surface modification of Hastelloy processed by the Cu mixed electric discharge alloying technique

Surface modification of Hastelloy processed by the Cu mixed electric discharge alloying technique

A review: advancements in fluoro-based polymers for aggrandizing anti-galling and wear resistant characteristics

Effect of Lubricant Type on the Friction Behaviours and Surface Topography in Metal Forming of Ti-6Al-4V Titanium Alloy Sheets

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