Effects of die land length and geometry on curvature and effective strain of profiles produced by a novel sideways extrusion process

Zhou, Wenbin; Yu, Junquan; Lin, Jianguo; Dean, Trevor

doi:10.1016/j.jmatprotec.2020.116682

Cited by 24 publications

(13 citation statements)

References 32 publications

(43 reference statements)

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“…The theoretically predicted curvature is slightly greater than that from FE modelling and extrusion experiments [ 100 , 101 ]. This is because the effect of die land on flow velocity gradient across the die orifice is not considered due to its small length (2 mm); however, it could have an “unbending” or straightening effect on the extrudate [ 103 ], which still needs to be further considered by establishing more sophisticated model.…”

Section: Extrusion-bending Integrated Forming Methodsmentioning

confidence: 99%

Advances and Trends in Forming Curved Extrusion Profiles

Zhou

Shao

et al. 2021

Materials

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Curved profiles/sections have been widely used for manufacturing lightweight structures with high stiffness and strength due to aerodynamics, structural properties, and design reasons. Structural components fabricated using curved aluminum profiles satisfy the increasing demands for products used in many high-technology industries such as aerospace, shipbuilding, high-speed rail train, and automobile, which possess the characteristics of lightweight, high strength/stiffness relative to weight, superior aerodynamics performance, and aesthetics. In this paper, the advances and trends in forming techniques of curved extrusion profiles of metal alloys have been reviewed. The curved profile forming techniques are classified into three major categories: conventional cold bending technique, stress/moment superposed cold bending technique, and extrusion-bending integrated forming technique. Processes for innovative development in the field of forming curved profiles are identified; the extrusion-bending integrated technique which can directly form the billets into curved profiles by one single extrusion operation possesses the full potential for further innovation. Due to the nature of the research to date, much of the work referred to relates to hollow circular and rectangular tube cross-sections.

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Section: Extrusion-bending Integrated Forming Methodsmentioning

confidence: 99%

Advances and Trends in Forming Curved Extrusion Profiles

Zhou

Shao

et al. 2021

Materials

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“…In the modeling of bulk metal forming, there are a few options to choose from, such as the Coulomb friction law [15][16][17], the constant shear (Siebel) friction law [18][19][20][21][22][23][24], both Coulomb and constant shear friction laws [25,26], general ones [27][28][29] or the integrated law, i.e., Coulomb constant shear friction law [9,14,[30][31][32][33]. Being naturally more flexible and, hence more relevant to real-life manufacturing than conventional Coulomb and constant shear friction laws, the Coulomb constant shear friction law is widely used in FEA of metalworking.…”

Section: Introductionmentioning

confidence: 99%

Derivation of the Coefficients in the Coulomb Constant Shear Friction Law from Experimental Data on the Extrusion of a Material into V-Shaped Channels with Different Convergence Angles: New Method and Algorithm

Bobrovskij

Khaimovich

Bobrovskij

et al. 2022

Metals

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The combined Coulomb constant shear friction law is widely used in commercial and research software for the finite-element analysis (FEA) of metalworking and is naturally more flexible and hence, more relevant to real-life manufacturing than the individual Coulomb and constant shear friction laws. In this work, a new mathematical model of coefficients in the Coulomb constant shear friction law for extruding a metal through narrow V-shaped channels with small convergence angles has been developed and evaluated and compared with laboratory measurements. The extrusion of the model material (lead) through narrow V-shaped channels with small convergence angles varying from 0 to 3.5 degrees has been studied. The Coulomb friction coefficient µ and the constant friction factor m appear to be independent of the dimension ratio and are influenced mostly by roughness and range from µ = 0.363 (with lubricant) to µ = 0.488 (without lubricant) and from m = 0.726 (with lubricant) to 0.99 (without lubricant). The relative length dominated by the Coulomb friction law is less than 1%, and the Coulomb’s coefficient of friction can be approximated as ½ the constant shear friction factor for all tested cases. The developed method and algorithm can be used in both FEA of manufacturing processes and efficiency tests for lubricants used in metalworking.

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“…Shiraishi et al [7][8][9] used an inclined die to obtain pipes and bars with curvature and found that the exit height and the inclination angle of the die are important factors that affects the curvature of the products. Zhou et al [10][11][12][13] developed differential velocity sideways extrusion (DVSE) process to directly manufacture curved profiles from conventional billet material in one operation. The results showed that punch speed ratio, extrusion ratio, die land length and die land transition corner are the factors affecting the curvature of DVSE process.…”

Section: Introductionmentioning

confidence: 99%