Thermal Stability of WB2 and W-B-N Films Deposited by Magnetron Sputtering

• 来源期刊: 金属学报（英文版）
• 年，卷（期）: 2019,（1）
• 页码范围: 136-144
• 页数: 9页
• 语种: 英文

摘要

The work is mainly to study the thermal stability including the phase stability,microstructure and tribo-mechanical properties of the A1B2-type WB2 and W-B-N (5.6 at.％ N) films annealed in vacuum at various temperatures,which are deposited on Si and GY8 substrates by magnetron sputtering.For the WB2 and W-B-N films deposited on Si wafers,as the annealing temperature increases from 700 to 1000 ℃,a-WB (700 ℃) and Mo2B5-type WB2 (1000 ℃) are successively observed in the AlB2-type WB2 films,which show many cracks at the temperature ≥ 800 ℃ resulting in the performance failure;by contrast,only slight α-WB is observed at 1000 ℃ in the W-B-N films due to the stabilization effect of a-BN phase,and the hardness increases to 34.1 GPa first due to the improved crystallinity and then decreases to 31.5 GPa ascribed to the formation of α-WB.For the WB2 and the W-B-N films deposited on WC-Co substrates,both the WB2 and W-B-N films react with the YG8 (WC-Co) substrates leading to the formation of CoWB,CoW2B2 and CoW3B3 with the annealing temperature increasing to 900 ℃;a large number of linear cracks occur on the surface of these two films annealed at ≥ 800 ℃ leading to the film failure;after vacuum annealing at 700 ℃,the friction performance of the W-B-N films is higher than that of the deposited W-B-N films,while the wear resistance of the WB2 films shows a slight decrease compared with that of the deposited WB2 films.