Analysis of Friction Factor in Cold Forging by using Ring with Triangular Boss Compression Test

Abstract

ABSTRACT The ring compression test, a quantitative method to evaluate various conditions of friction at the interface of the dies and work piece by the analysis of diametric (inner) change in the dimension and height of the ring in metal forming. After the compression, it is difficult to measure the inner diameter precisely due to nonuniform deformation. To overcome these difficulties in the conventional ring compression test, an alternative method named RTB-CT is proposed in which two types of geometries of the ring were used one is the ring with the equilateral triangular boss and the other is the ring with isosceles triangular boss. In conventional approach of determination of coefficient of friction of the lubricants, the Ring compression test was used. But, the accuracy of the results through this test was directly linked to the measurements of the different parameters of the compressed ring under the application of the lubricant and due to bulging effect of the ring, the measurement of the inner diameter was difficult. In proposed RTB-CT, this difficulty was overcome by eliminating the measurement of inner diameter of the deformed ring and using a boss on the ring which makes the process of measurement easier and accurate.