An optimal forward extrusion device proposed for numerical and experimental analysis of materials tribological properties corresponding to bulk forming processes

Analytical and numerical analyses of local loading forming process of T-shape component by using Coulomb, shear and hybrid friction models

“…The hybrid friction model is a Coulomb-Tresca friction model and has been used in analysis of plastic forming process [16,20].…”

“…In fact, the Coulomb friction model is available especially for elastic contact [11], although it is also widely used in bulk forming processes such as extrusion, forging, ring rolling [12][13][14][15]. While, the shear friction model is available for plastic material-die contact [16]. In recent years, a hybrid friction model (also named Coulomb-Tresca friction model) combined Coulomb and shear friction models has also been developed for some conditions where there exists local high normal pressure or local sliding with less normal pressure on the interface [17][18][19][20][21], which is for general elastic-plastic interfaces.…”

“…For aluminium extrusion process, Wang et al [27] recommended that the magnitude of friction between the material and container is determined by the extrusion friction test while the magnitude of friction in bearing channel is determined by the short sliding distance ball-on-disc test. In the finite element analysis of forward extrusion process, Coulomb friction model in the input container and output die regions and shear friction model in the conical die region were adopted by Gavrus et al [16]. The Coulomb friction model in contact interface between flank of rolling die and workpiece and the shear friction model in contact interface between addendum of rolling die and workpiece were adopted in slip-line field analysis of spine rolling process [28].…”

“…However, the predicted results shows a big difference between two friction models in ring gear forging. To analyze a forward extrusion process Gavrus et al [16] used the hybrid friction model (i.e. Coulomb-Tresca friction model) showing that it is necessary to consider rather a Coulomb friction model (m ¼ 1) for the input container and output die regions and a shear friction model ðμ ¼ 0Þ for the conical die.…”

“…The hybrid friction model also been used in FEM simulation by Ghassemali et al [20] to research the microforming process of pin, where μ ¼ 0:577 m was adopted. The importance of friction model in metal forming simulation has been emphasized [3,16]. However, the works on the local loading process by SM and FEM are all based on shear friction model [7,[29][30][31], so it is necessary to explore the role of friction model in local loading forming process.…”