High-Temperature Wear Performance of hBN-Added Ni-W Composites Produced from Combustion-Synthesized Powders

Abstract

This work reports on the spark plasma sintering (SPS) of self-propagating high-temperature-synthesis (SHS)-derived Ni-W and Ni-W-2wt%hBN (4:1 molar ratio of metals) powders. The synthesis was carried out from a mixture of NiO and WO3 using Mg + C combined reducers through a thermo-kinetic coupling approach. Experiments performed in the thermodynamically optimal area demonstrated the high sensitivity of combustion parameters and product phase composition to the amount of reducers and hBN powder. The powder precursors with and without the addition of hBN were consolidated using SPS at a temperature and pressure of 1300 °C and 50 MPa, respectively, followed by a thorough phase and microstructural characterization of the obtained specimens. SHS-derived powders comprised the nano-sized agglomerates and were characterized by a high sinterability. The specimens of >95% density were subjected to ball-on-plate dry sliding wear tests at a sliding speed of 0.1 ms−1 and a distance of 1000 m utilizing an alumina ball of 10 mm in diameter under a 15 N normal load. The tests were performed at a temperature of 800 °C. A significant improvement in wear behavior was demonstrated for SHS-processed composites in comparison with their counterparts produced via conventional high-energy ball milling technique owing to the phenomena of ‘micro-polishing’, cyclic ‘self-healing’ and fatigue. However, the decisive effect of hBN addition in imparting lubrication during an HT wear test was not confirmed.

Bioinspired and Multifunctional Tribological Materials for Sliding, Erosive, Machining, and Energy-Absorbing Conditions: A Review

“…Several others have reported superior tribological performance (reduction in CoF/wear rate/wear mechanisms, etc.) upon synergistic application of biotexturing and solid lubrication [61,76,144,145]. These structures can trap lubricants (wear debris may lead to rolling friction), reduce contact area, improve hydrodynamic pressure, and alter the contact interface, leading to improved wear resistance, reduced friction, and contributing to increased efficiency, durability, and reliability of mechanical systems, making them valuable tools in various industrial applications.…”

Solid Lubrication at High-Temperatures—A Review

“…So far, the results on tribological studies of hBN as a solid lubricant give no clear idea of its usage. On the one hand, few studies report a positive influence of hBN in solid lubrication [ 3 , 10 , 74 , 75 , 76 ], while others state its negative or no effect on lubrication [ 77 , 78 , 79 , 80 ]. A decrease in CoF and wear rate with an increase in temperature up to 800 °C in Ni/hBN coating on stainless steel was perceived [ 75 ].…”

Progress in Sustainable Recycling and Circular Economy of Tungsten Carbide Hard Metal Scraps for Industry 5.0 and Onwards

“…Cemented carbides are metal matrix composites encompassing a hard carbide phase (mostly WC, 50% to 90% by weight) distributed/embedded/cemented as an aggregate into a soft metallic binder phase (usually Co, Fe, Ni; 0% to 35% by weight), exploiting the widely recognized powder metallurgical [4][5][6][7][8][9] and additive manufacturing (3D printing) [3] techniques. Frequently, the alloying of other metals (or their carbides), such as Ti, Ta, Nb, etc., to achieve the desired properties is also conducted [10][11][12][13][14]. The final composites are noted for their impeccable combination of properties, such as excellent hardness, toughness, refractoriness, and mechanical strength, which immensely benefit applications (up to 600 • C) mainly concerning extreme wear loss (mainly abrasion and impact) [11,[15][16][17][18].…”