COLD SPRAYED COATINGS WITH DUAL NANOPARTICLE REINFORCEMENTS FOR WEAR AND CORROSION PROTECTION

As a form of additive manufacturing, the use of cold spray has made significant strides since different-sized particles were explored in the process. There is proof that micron-sized particles down to nanoparticles enhance the mechanical material properties of a substrate in wear resistance. Micron- and submicron-sized particles are beneficial, but due to their low relative surface areas, they tend to exhibit pull out more often and do not adhere to a substrate as well as a nanoparticle. Using nanoparticle metal and dual ceramic matrix reinforcements, six composites were fabricated through cryomilling and then applied to an aluminum substrate as a cold sprayed coating. Using nano-boron carbide (nB4C) and boron nitride nanoplatelets (BNNP) at various combinations up to 2 vol%, an increase of 11.59% in hardness from the control was achieved. Wear testing of each coating was performed, but most of the tests drove through the coatings into the substrate, indicating more refinement of the testing parameters is required. Additionally, corrosion testing was performed on cold sprayed samples for 500- and 2,000-hr trials in a salt fog chamber, revealing underlying pitting corrosion and galvanic corrosion vulnerabilities of the coatings. In the right application, the U.S. Navy could potentially use these coating materials in parts that are subjected to austere marine environments.

Department dc:contributor.department

Mechanical and Aerospace Engineering (MAE)

Grantor dc:publisher

Monterey, CA; Naval Postgraduate School

Year dc:date.issued

2020

Author dc:creator

• Norrell, Travis

Advisor dc:contributor.advisor

• Nieto, Andy

Statement dc:rights

• This publication is a work of the U.S. Government as defined in Title 17, United States Code, Section 101. Copyright protection is not available for this work in the United States.

Handle dc:identifier.uri

https://hdl.handle.net/10945/65411

OAI identifier oai:identifier

oai:calhoun.nps.edu:10945/65411