Near surface shear cracks in dawn cobalt and magnesium wires

• Autorzy: Eickemeyer, J. , Falter, M. , Opitz, R. , Güth, A.
• Języki publikacji: EN

Abstrakty

EN

Wire drawing experiments were performed under laboratory conditions using the hexagonal close packed metals cobalt and magnesium. It was experimentally shown that the material flow in the peripheral region controls the drawability of both metals at ambient temperature. Further, it became apparent that the roughness peak parameter Rz(DIN) was a reasonable measure to characterise the wire surface with regard to the drawability. Rz(DIN) < 2 micro m resulted in a successful drawing process. On the other hand, Rz(DIN) > 4 micro m led to shear crack formation and failure of the cobalt wires. Magnesium was less susceptible to surface roughness effects on shear crack formation than cobalt. Thicker lubricant films were tolerated and even needed.

Słowa kluczowe

PL

wytrzymałość materiałów; smarowanie; chropowatość powierzchni; pękanie powierzchniowe

EN

metal forming; cold drawing; surface cracking; surface roughness; lubrication regime

• Czasopismo: International Journal of Applied Mechanics and Engineering
• Rocznik: 2002
• Tom: Vol. 7, no 3
• Strony: 771-782
• Opis fizyczny: Bibliogr. 8 poz., rys., tab.

Twórcy

autor

Eickemeyer, J.

• Leibniz Institute for Solid State and Materials Research Dresden P.O. Box 270016, D-01171 Dresden, GERMANY,

autor

Falter, M.

• Leibniz Institute for Solid State and Materials Research Dresden P.O. Box 270016, D-01171 Dresden, GERMANY

autor

Opitz, R.

• Leibniz Institute for Solid State and Materials Research Dresden P.O. Box 270016, D-01171 Dresden, GERMANY

autor

Güth, A.

• Leibniz Institute for Solid State and Materials Research Dresden P.O. Box 270016, D-01171 Dresden, GERMANY

Bibliografia

• [1] Backofen W.A. (1972): Deformation Processing. - Addison-Wesley Publishing Company, Reading, Ma.
• [2] Couret A. and Caillard G. (1991): Prismatic glide in divalent H.C.P. metals. - Phil. Mag., vol.A63, No.5, pp. 1045-1057.
• [3] Eickemeyer J., Falter M., Opitz R., Giith A. and Wendrock H. (2001): Near surface material flow as a limiting factor in metal cold drawing, In: Proc. of 2nd World Tribology Conference (F. Franek, W. J. Bartz and A. Pauschitz, Eds.). - Vienna, Sept. 3-7, 2001, p.375.
• [4] Eickemeyer J., Giith A., Opitz R. and Reichert J. (1999): Prevention of surface crack formation in cobalt wire drawing. - Advanced Technology of Plasticity (M. Geiger, Ed.), vol.3, pp.1775-1780.
• [5] Eickemeyer J., Weinhold H., Wellert H. and Franke P. (1984): Surface markings on hydrodynamically drawn wires. - Scipta Metallurgies vol.18, pp. 1375-1378.
• [6] Hurricks P.L. (1970): The mechanism of fretting - a review. - Wear, vol.15, pp.389-409.
• [7] Schey J.A. (1984): Tribology in Metalworking. - ASM, Metals Park, Ohio.
• [8] West A. R. (1992): Grundlagen der Festkorperchemie. - VCH-Verlag, Weinheim.