کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
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617905 | 1455011 | 2012 | 9 صفحه PDF | دانلود رایگان |
It is well known that dimpled surface can improve tribological characteristics. The fundamental aim of the present research is to demonstrate the process of making micro-dimples by ultrasonic nanocrystalline surface modification (UNSM) technology and to evaluate its effects on tribological characteristics. Ball-on-disk test was performed in order to reveal the influence of mechanism and micro-dimples. UNSM-treated surface is compared to ground surface and friction coefficient of the UNSM-treated surface has been reduced by about 25%, which is a significant phenomenon in improving tribological properties of mating surfaces. Wear volume loss of UNSM-treated surface has also been reduced by about 60%. Scanning electron microscopy (SEM) and surface roughness profile measurement were utilized to study the worn surface.
► EBSD micrographs show that more surface plastic deformation is observed in the surface layer of the UNSM-treated surface comparing to the untreated surface.
► The key point for realizing the surface nanocrystallization of a bulk material is to introduce interfaces into the surface layers, so that its microstructure is transformed into nano-sized crystallites.
► UNSM is an effective technology to realize the surface nanocrystallization on metallic materials.
Journal: Wear - Volumes 286–287, 15 May 2012, Pages 136–144