Mechanical and tribological properties of multi-element (AlCrTaTiZr)N coatings

✍ Scribed by Chia-Han Lai; Keng-Hao Cheng; Su-Jien Lin; Jien-Wei Yeh

• Publisher: Elsevier Science
• Year: 2008
• Tongue: English
• Weight: 934 KB
• Volume: 202
• Category: Article
• ISSN: 0257-8972
• DOI: 10.1016/j.surfcoat.2008.01.014

✦ Synopsis

Multi-element (AlCrTaTiZr)N coatings are deposited onto Si and cemented carbide substrates by reactive RF magnetron sputtering in an Ar + N 2 mixture. The influence of substrate bias voltage, ranging from 0 to -200 V, on the microstructural, mechanical and tribological properties of these nitride coatings is studied. A reduction in concentration of N and Al is observed with increasing substrate biases. The (AlCrTaTiZr)N coatings show the face-centered-cubic crystal structure (B1-NaCl type). The use of substrate bias changes the microstructure of the (AlCrTaTiZr) N coating from the columns with microvoids in boundaries to the dense and less identified columns. The compressive macrostress increases from -0.9 GPa to -3.6 GPa with an increase of substrate bias. The hardness and adhesion increase to peak values of 36.9 GPa and 60.7 N at the bias voltage of -150 V, respectively. The tribological properties of the (AlCrTaTiZr)N coatings against 100Cr6 steel balls are evaluated by a ball-ondisc tribometer with a 10 N applied load. With an increase of substrate bias, the wear rate reduces while the friction coefficient almost keeps constant at 0.75. The lowest wear rate of 3.65 × 10 -6 mm 3 /Nm is obtained for the (AlCrTaTiZr)N coating deposited at the bias voltage of -150 V.