Sliding wear behavior of laser surface hardened austempered ductile iron

Journal of Materials Research and Technology

卷:9

Zhenpu Zhang¹  Yuming Pan²  Hongyu Yang²  Gary C. Barber²  Feng Qiu³  Xue Han³ 

[1] Automotive Tribology Center, Department of Mechanical Engineering, School of Engineering and Computer Science, Oakland University, Rochester, MI, 48309, USA;

[2] Key Laboratory of Automobile Materials, Ministry of Education and School of Materials Science and Engineering, Jilin University, Renmin Street NO. 5988, Changchun 130025, China;

关键词: Laser surface hardening;    Austempering process;    Wear behavior;    Debris;   

DOI  :  

来源: DOAJ

【 摘 要 】

This study describes the laser surface hardening process effect on microstructures produced and their wear behavior. Ductile iron samples were austempered at three different austempering temperatures: 232 °C/288 °C/398 °C respectively. Then, the laser surface hardening process was applied on each sample. Different laser gaps were designed: 1.5mm/3mm/4 mm. The microstructures were observed using optical microscopy and tribo-tests were run using a UMT-3 tribo tester. A Rockwell hardness tester was used to measure the hardness after heat-treatment. Optical microscopy and SEM were used to observe the different microstructures and their distribution on the worn surface. The results showed that the laser processing generated ledeburite, martensite, or tempered bainite microstructures. Vickers hardness tests were carried out on these microstructures. The original needle-like microstructures were observed on the samples with 4 mm laser gap but not with 1.5 mm or 3 mm laser gap. This is because part of the 4 mm laser gap is beyond the laser heat effected zone. Generally, severe ploughing wear and smearing wear were observed on the tempered bainite zone but not the bainite zone. Debris was generated during the tribo-tests and led to three body abrasive wear which not only resulted in higher wear loss, but also polished the worn surface.

【 授权许可】

Unknown