STUDY ON THE INFLUENCE OF 1 AND 15μm PITCH VALUES ON THE APPARENT NANOMECHANICAL PROPERTIES OF LASER POWDER BED FUSION-PRODUCED CuCrZr ALLOY

Abstract

Material deformation due to nanoindentation is well known. However, the deformation of a material, indentation cavity, and piled-up region drastically increases and nanohardness significantly decreases if the nanoindentation is performed in such a way that the deformation of one nanoindentation affects the others. This situation arises in various materials when they are subjected to tribological application such as pantograph assembly in electric trains and contact between the electrical power supply plug and pins. This situation has been addressed in this study and the quantitative reduction in nanohardness has been evaluated in detail. In this work, the nanoindentation was performed on the laser powder bed fusion (LPBF) CuCrZr alloy specimen under a load condition of 4500[Formula: see text][Formula: see text]N. This test was conducted at 100 points with an array of [Formula: see text] at a 1[Formula: see text][Formula: see text]m pitch value. Two significant findings were identified in this work. First, the indentation impression was smaller and the corresponding nanohardness and contact stiffness values were higher in the first column of 10 nanoindentations and the first row of 10 nanoindentations. The remaining 80 nanoindentations displayed contrasting behavior compared to the initial 20 nanoindentations due to the prior deformation of nearer regions. Nanohardness value decreased parabolically from the low deformation to the high deformation region. This finding was validated by increasing the pitch to 15[Formula: see text][Formula: see text]m under the 4500[Formula: see text][Formula: see text]N load conditions. The piled-up region around the impression of indentation changed from a semi-circular shape at a 15[Formula: see text][Formula: see text]m pitch value to a cone shape at a 1[Formula: see text][Formula: see text]m pitch value. These findings will be beneficial for industries during the design of materials and will help reduce material failures resulting from tribological activities.