Influence of coefficient of friction between punch-blank interface on formability of friction stir welded aluminum tailor welded blanks – An experimental and finite element simulation investigations
N Malleswararao Battina, Hari Krishna Chirala, I. Ramu, Obula Reddy Kummitha, Lakshmi Narayana Veeravalli, Srinivasa Raju Pericherla
Abstract
The influence of the coefficient of friction between punch-blank interface on the formability of friction stir welded aluminum tailor welded blanks was studied. Experimental and finite element investigations were performed to evaluate the formability with four different lubricants like dry lubricant, graphite in water, graphite in machine oil, and Teflon sheet (TS). During simulation, the boundary condition of the punch-blank interface was assigned as a frictional contact and the assigned value is the coefficient of friction value of the respective lubricant. To carry out the simulation, the entire blank was divided into three zones. It has been found that the coefficient of friction between punch-blank interfaces has a significant influence on formability. In the four lubrication conditions, the dry lubrication applied blank exhibited the lowest formability properties, and the TS applied blank exhibited superior formability properties in all aspects such as punch load-carrying capacity, limiting dome height, forming limit diagrams, and strain distribution profiles (experimentation and simulation). The experimental and simulation have a good agreement in all strain conditions. The standard deviation between the experimental and simulation results is ±10%.