Abstract
In this study, the effect of tool asperity and the lubrication condition on tribological behavior, inner surface characteristics and deformation limit of metallic microtube in flaring test were investigated experimentally. The microtube used in this experiment is stainless steel (SUS 316L) and has a 500 μm outer diameter and 50 μm thickness. The flaring tests of the microtube using a conical tool were conducted under dry and two kinds of lubricated-contact conditions as well as different tool surface roughnesses. As a result, it is found that the flaring load and deformation limit of the microtube increase when using a rougher tool. In addition, a spray-type fluorocarbon resin, as a solid lubricant, decreases the above characteristics, but lubrication oil, as a liquid lubricant, exhibits different behavior. Meanwhile, the surface roughnesses of the inner surface of the microtube along axial and circumferential directions reduce when using a rougher tool. From these results, the surface smoothing mechanism of the microtube in the flaring test and the influencing parameters on tribological behavior are discussed.
