Improved mechanical properties of W-Zr-B coatings deposited by hybrid RF magnetron – PLD method
Rafał Psiuk, Michał Milczarek, Piotr Jenczyk, Piotr Denis, Dariusz M. Jarząbek, Piotr Bazarnik, Marcin Pisarek, Tomasz Mościcki
Abstract
In this work, novel W-Zr-B coatings were developed by a hybrid process combining pulsed laser deposited ZrB 2 and radio frequency magnetron sputtered W 2 B 5 . The influence of the laser power density on the structure and mechanical properties of the deposited films was studied. Addition of zirconium causes a change in the structure of the deposited films from columnar to mainly amorphous. The nanoindentation tests and compression of nanopillars showed that doped W-Zr-B layers are still super-hard and incompressible in comparison to WB 2 films without doping, but they change their behaviour from brittle to ductile. Films obtained with a fluence of 1.06 J/cm 2 are superhard (H = 40 ± 4 GPa) and incompressible (12 ± 1 GPa), but possess a relatively low Young’s modulus (E = 330 ± 32 GPa) and a high elastic recovery (W e = 0.9). Further increase in the fluence causes films to consist of deeply embedded fragments of laser ablated ZrB 2 target in the deposited layer. Taking into account that the particles are made of ZrB 2 which possess extraordinary thermal properties, and the matrix is made of W-Zr-B, a super-hard material, such a composite can also be interesting for industrial applications.