Metallic glasses possess unique properties, such as; hardness, high strength, outstanding corrosion and wear resistance. These properties make them excellent candidates for applications ranging from gears, dry bearings, medical instruments, surface coatings and as structural materials – among many others. Owing to their surface treatment/coating capabilities, they have been receiving increasing attention from researchers in the field of surface engineering. To date, a plethora of literature exists regarding the friction and wear behavior of metallic glasses during sliding contact. Nonetheless, further research is required because new metallic glasses are being designed to improve their functionality. In particular, the novel palladium based metallic glass that has displayed superior tribological performance thereby becoming a potential material to solve contact induced failures and improve the reliability of many engineering applications.
In addition, little has been done regarding metallic glasses under lubricated-contact conditions, even though the contact interfaces of practical engineering components are under several types of lubricants.
To this note, a team of researchers at Texas Technical University led by Jaeho Lee, Muyang He, Dr. Golden Kumar, Zhonglue Hu and led by Professor Chang-Dong Yeo from the Department of Mechanical Engineering in collaboration with Professor Edward L. Quitevis, Dr. Vidura D. Thalangamaarachchige from the Department of Chemistry & Biochemistry investigated the friction and wear of a palladium-rich amorphous alloy under dry and ionic liquid-lubricated conditions. Their aim was to compare the obtained results of the palladium rich alloy with those of crystalline pure palladium, thereby giving them fundamental insights into the formers’ friction and wear behavior. Their work is currently published in the research journal, Wear.
In brief, the research team initiated their research by first synthesizing palladium-rich metallic glass (Pd43Cu27Ni10P20). Next, the tribological performance of amorphous palladium rich glass alloy and pure crystalline palladium under dry and lubricated contact condition was investigated through the reciprocating ball-on-disc tests. The researchers then applied a particular ionic liquid as lubricant. Lastly, under the controlled contact conditions, the researchers measured the in-situ friction and ex-situ wear and compared them quantitatively.
The authors observed that, under the dry contact conditions, the amorphous palladium alloy showed much lower coefficient of friction and wear than the crystalline palladium. Additionally, three wear mechanisms were identified on the crystalline palladium, whereas the amorphous palladium alloy showed single dominant wear mechanism. The researchers also noted that once the ionic liquid was applied to the contact interface, it significantly improved the friction and wear of both amorphous and crystalline palladium samples.
In summary, the study by Texas Technical University scientists presented an in-depth assessment of the friction and wear resistance of a palladium-rich amorphous alloy, under both dry contact and ionic liquid lubricated conditions. Generally, they observed that only abrasive wear mechanism was present on both types of palladium samples. Nonetheless, the ionic liquid lubrication was seen to be more effective to the crystalline palladium sample partly because of the tribofilm formation on the surface.
Jaeho Lee, Muyang He, Chang-Dong Yeo, Golden Kumar, Zhonglue Hu, Edward L. Quitevis, Vidura D. Thalangamaarachchige. Friction and wear of Pd-rich amorphous alloy (Pd43Cu27Ni10P20) under dry and ionic liquid (IL) lubricated conditions. Wear, volume 408–409 (2018) page 190–199.Go To Wear