Article: Imbriglio, SI; Hassani-Gangaraj, M; Veysset, D; Aghasibeig, M; Gauvin, R; Nelson, KA; Schuh, CA; Chromik, RR; “Adhesion Strength of Titanium Particles to Alumina Substrates: A combined cold spray and LIPIT study”, Surface & Coatings Technology, 361: 403-412
Abstract: The cold spray process and laser-induced projectile impact test (LIPIT) are used to deposit Ti powder particles on sintered polycrystalline Al2O3. Whereas LIPIT allows real-time observations of single particle impact and measurement of particle impact velocity, cold spray rapidly and simultaneously deposits particles with a wide range of deposition velocities and sizes. By use of these two techniques, the effect of particle velocity and substrate morphology on adhesion strength of single splats is investigated. The critical velocity for deposition is identified to be approximately 580 m/s for the Ti/Al2O3 system when using LIPIT and particles of 10 mu m. Above the critical velocity, flattening ratio (FR) is also evaluated and observed to be linearly dependent on the particle impact velocity. Splat adhesion testing is performed on LIPIT-deposited as well as on cold spray-deposited powder particles to measure adhesion strength. This analysis shows that adhesion strength is highly affected by local substrate surface morphology, where particles bond more weakly to relatively smooth portions of the substrate. Therefore, mechanical bonding plays a significant role in adhesion. Also, adhesion strength decreases with an increase in FR and therefore velocity. This decrease can be associated with fracture of the ceramic substrate and rebound forces.
Funding Acknowledgement: Natural Sciences and Engineering Research Council of Canada (NSERC) Strategic Grants Program; US Army Research Laboratory [W911NF-15-2-0034]; U.S. Army Research Office through the Institute for Soldier Nanotechnologies [W911NF-13-D-0001, W911NF-18-2-0048]; Office of Naval Research DURIP [N00014-13-1-0676]
Funding Text: RRC and SII acknowledge the assistance of Dr. Phuong Vo and Jean-Francois Alarie at the National Research Council Canada for technical support with the cold spray equipment and Drs. Thomas Schmitt and Jolanta Sapieha from Polytechnique Montreal for technical support and access to the scratch tester. This work was supported by the Natural Sciences and Engineering Research Council of Canada (NSERC) Strategic Grants Program.MHG and CAS acknowledge support from the US Army Research Laboratory, Contract: W911NF-15-2-0034, “Development of Additive Manufacturing and Advanced Materials Processing for the DOD”. DV and KAN acknowledge support from the U.S. Army Research Office through the Institute for Soldier Nanotechnologies, under Cooperative Agreement Numbers W911NF-13-D-0001 and W911NF-18-2-0048 as well as support for equipment through the Office of Naval Research DURIP Grant No. N00014-13-1-0676.