Nanodiamond powder compaction via laser shockwaves: Experiments and finite element analysis

Laser shock sintering (LSS) is an innovative technique employing mechanical forces to densify powders. It can impart compressive stresses into material to improve the relative density and generate residual stresses to enhance the fatigue strength. In this work, LSS of nanodiamond powders embedded in polycrystalline cubic boron nitride (PCBN) substrate was experimentally investigated using a 1064 nm, 10 ns Q-switched Nd:YAG laser with a peak power density of 6.37 GW/cm2. Finite element simulation (FEM) was applied to predict the mechanical deformations induced by LSS. The dynamic analysis by ABAQUS/Explicit and static analysis by ABAQUS/Standard were performed in detail to predict the residual stress field and densification of nanodiamond powder compacts. The predicted densification of nanodiamond powder compacts is in agreement with the experimental data for single and multiple laser shocks.

Laser shock compaction of nanodiamond powders inside the holes of a substrate.Figure optionsDownload as PowerPoint slideHighlights
► Laser shock sintering is a novel technique demonstrated for nanodiamond powders.
► Hardness achieved is 30% of high temperature/high pressure sintered nanodiamond.
► Phase transition to diamond-like carbon and nanocrystalline graphite occurs.
► Finite element simulation predicted the densification of nanodiamond powders.