Tribology of Si3N4 containing in-situ grown Si2N2O processed from oxidized α - Si3N4 powders. Issue 12 (15th June 2021)

• Record Type: Journal Article
• Authors: Qadir, Awais; Ben Zine, Haroune Rachid; Pinke, Peter; Dusza, Jan
• Is Part Of: Ceramics international. Volume 47:Issue 12(2021)
• Page Start: 17417
• Page End: 17426
• Publication Date: 2021-06-15
• Subjects: Si3N4 -- Si2N2O -- In-situ Si2N2O -- Mechanical properties -- Tribology -- Wear mechanisms; Ceramics -- Periodicals; Céramique industrielle -- Périodiques; Ceramics; Periodicals; Electronic journals; 666
• DOI: 10.1016/j.ceramint.2021.03.058
• Languages: English
• ISSNs: 0272-8842

Abstract

Abstract: Silicon nitride ceramics containing in-situ grown Si2 N2 O were prepared from oxidized silicon nitride powders by hot isostatic pressing (HIP) at 1500 °C and 1700 °C in a nitrogen gas environment under 20 MPa for 3 h. In case of systems sintered at 1700 °C, the volume fraction of the silicon oxynitride (Si2 N2 O) increased, and the β - Si3 N4 phase decreased with the increase of oxidation time. The tribological behavior of the materials was studied by the ball-on-disc method under dry sliding conditions at room temperature under an applied load of 5 N with a sliding speed of 0.05 m/s using Si3 N4 ball as a tribo-partner. For the systems sintered at 1700 °C, the coefficient of friction (COF) values were between 0.8 and 0.76 at the start, and started decreasing with the increasing sliding distance, at 1000 m of sliding distance the values were between 0.65 and 0.6. The lowest COF value was measured for the system with unoxidized α-Si3 N4 powder sintered at 1700 °C with the value of 0.65. The lowest wear rate, 1.224 x 10 -4 mm 3 /Nm, was measured for the system with 10 h oxidized α-Si3 N4 powder sintered at 1500 °C. Fractographical analyses of the wear track revealed that the main wear mechanisms were abrasive wear with grain pull-out, micro-cracking, and debris formation together with tribo-film formation.