Galling phenomena in metal forming

Dohda, Kuniaki; Yamamoto, Masahito; Hu, Chen; Dubar, Laurent; Ehmann, Kornel F.

doi:10.1007/s40544-020-0430-z

Cited by 40 publications

(17 citation statements)

References 87 publications

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“…After computational surface chemistry [15], titanium had less of a possibility of change in the DOS (Degree of State) of electrons from its metallic bonding to covalent one in the SiC. In addition to the above chemical explanation on the galling behavior, the mechanical interaction between the SiC coating and titanium must be taken into account after [16].…”

Section: Introductionmentioning

confidence: 99%

Thick β-SiC CVD-Coated SiC Die System for Dry Cold Forging of Metals

Aizawa

Yoshino

Ito³

et al. 2020

Crystals

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A thick β-SiC CVD (chemical vapor deposition)-coated SiC device was developed as a new punch and die system for dry, cold forging of pure titanium and austenitic stainless-steel works. This β-SiC coating thickness was 4 mm, enough to make mechanical machining of a cavity into β-SiC coating core die. These β-SiC-coated punch and core dies were fixed into the cassette die for dry, cold forging experiments. The stainless steel and titanium wires with diameters of 1.0 mm were employed as the work material. Different from the conventional metallic and ceramic die systems suffering from work material transfer, this system sustained the galling-free cold, dry forging behavior up to a higher reduction of thickness than 30%. The power to stroke the relationship was in situ monitored to describe this forging behavior up to the specified reduction of the wires together with observations on the geometric change from a circular wire to a pentagonal prism bar. Precise scanning electron microscopy-electron-dispersive X-ray spectroscopy (SEM-EDX) analyses were performed to describe the material compatibility on the contact interface between β-SiC coating and elastoplastically deforming works.

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Section: Introductionmentioning

confidence: 99%

Thick β-SiC CVD-Coated SiC Die System for Dry Cold Forging of Metals

Aizawa

Yoshino

Ito³

et al. 2020

Crystals

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“…Galling phenomena between the workpiece and tool lead to deterioration on the surface of finished products (Figure 13) and severe wear of the tools. The galling phenomenon is made clearer by measuring the heat generated by friction and contact pressure [36]. Galling is a consequence of adhesive wear, which is defined as the separation of material particles due to adhesive tacking on the contact surfaces.…”

Section: Surface Roughnessmentioning

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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“…No improvement in drawability was experienced even when using ZrO 2 , SiC and Si 3 N 4 die materials in deep drawing of titanium sheets. As surveyed in [ 3 ], these galling processes were difficult to be prevented from upsetting and shaping the pure titanium works with high reduction of thickness without an innovative change of die materials. Thick β -SiC coated SiC die material was the first candidate to put the anti-galling forging in dry and cold into practice [ 4 , 5 , 6 ].…”

Section: Introductionmentioning

confidence: 99%

Free-Forging of Pure Titanium with High Reduction of Thickness by Plasma-Carburized SKD11 Dies

et al. 2021

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A tool steel type SKD11 punch was plasma carburized at 673 K for 14.4 ks at 70 Pa to make carbon supersaturation. This carburized SKD11 punch was employed for upsetting the pure titanium wire with the diameter of 1.00 mm up to the reduction of thickness by 70% in a single shot. Its contact interface to titanium work was analyzed to describe the anti-galling behavior in this forging. Little trace of titanium proved that the galling process was suppressed by the in situ solid lubrication. The isolated free carbon agglomerates are wrought as a solid lubricant to sustain the galling-free forging process. This anti-galling upsetting reduced the residual strains in the forged wires. A long titanium wire with a length of 45 mm was incrementally upset to yield the titanium ribbon with a thickness of 0.3 mm, the width of 2.3 mm, and the length of 50 mm. The grain size of original pure titanium was much reduced to 2 μm on average. A micro-pillared microtexture was imprinted onto this forged titanium ribbon.

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Galling phenomena in metal forming

Cited by 40 publications

References 87 publications

Thick β-SiC CVD-Coated SiC Die System for Dry Cold Forging of Metals

Thick β-SiC CVD-Coated SiC Die System for Dry Cold Forging of Metals

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

Free-Forging of Pure Titanium with High Reduction of Thickness by Plasma-Carburized SKD11 Dies

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