In lubro 3D measurement of oil film thickness at the interface between tool and workpiece in sheet drawing using a fluorescence microscope

In order to understand quantitatively the micro-contact and lubricant behavior at the interface between a tool and a workpiece in sheet drawing, a method for mapping the oil film thickness in lubro has been developed. This is based on the use of a fluorescence microscope. It is shown, firstly, that the in situ oil film thickness between the tool and the workpiece can be measured three dimensionally, and, secondly, that the in situ surface topography of the workpiece can be visualized clearly. From the 3D surface topography, the permeation of the trapped lubricant into the real contact area can be observed.