%0 Journal Article
%T One Contribution to the Friction Investigation in Bulk Metal Forming
%A Igor Ka mar ik
%A Dejan Movrin
%A Aljo a Ivani evi
%J Journal for Technology of Plasticity
%D 2011
%I 
%R 10.2478/v10211-011-0001-4
%X Friction is resistance to relative motion when one body slides over another. In metal forming operations, both sheet metal and bulk metal forming, friction is undesirable but also unavoidable occurrence. It has negative impact on main process parameters as well as on workpiece quality. In order to obtain accurate results in metal forming experiments or simulations, the precise value of friction has to be known. In this paper several methods for friction evaluations, such as ring test, forward bar extrusion, backward - forward hollow extrusion, twist extrusion are presented and analyzed. A new double backward extrusion model is proposed.
%K Friction models
%K Ring test
%K Friction calibration curves
%K Double backward extrusion
%U http://versita.metapress.com/content/m8354602175j1767/?p=502d4545876e43318cc7ccffb17221c3&pi=4