FRICTION AND LUBRICATION in sheet metal forming are influenced by such parameters as material properties, surface finish, temperature, sliding velocity, contact pressure, and lubricant characteristics. The parameters that affect friction and lubrication are schematically shown in Fig. 7.1. Depending on these parameters, the performance of a lubricant and the coefficient of friction (COF) vary. ...

We describe a new methodology that enables dynamical control of motion through modulating the friction at coating surfaces by exposing to UV light. The principle is based on reversible switching of the surface topographies of the coating by light. The coating surface transfers from flat in the dark to corrugated in the presence of UV by forming regular ridge-like line gratings. Both the static ...

Frictional shear stress is usually determined by utilizing the coefficient of friction or the constant friction factor models. The present study deals with finite element analysis of double cup extrusion process to determine the relationship between constant friction factor (m) and coefficient of friction (µ), since the metal flow in this process is very sensitive to frictional conditions. Ther...

The automotive industry has undergone significant advancements and changes over time, resulting in the use of more complex parts modern vehicles. As a consequence, used manufacturing process are subject to higher stress levels, which reduce their service life. To mitigate this issue, surface treatments can be applied improve mechanical properties tools. In study, we examined impact on reducing ...

Ferritic stainless steels have been widely used to substitute austenitic because of their lower cost and higher deep drawing capacity. However, failures, such as shear fracture, observed in parts with small radii during the process applications where both bending stretching occurs. Conventional techniques, failure criterion consideration, finite element method, forming limit diagram, are unable...

The dynamics and the transition to the centrifugal regime are studied analytically and numerically for particles in rotating drum. The importance of the particle-wall friction coefficient is demonstrated by studying first the motion of one non-rotating particle where three different regimes are found in the transition to the centrifugal motion. When a few rotating particles are considered, they...