کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
1662636 | 1008446 | 2007 | 11 صفحه PDF | دانلود رایگان |
Plasma-sprayed, molten nickel particles (∼ 60 μm diameter) were photographed during impact on oxidized 304L stainless steel surfaces that were maintained at either room temperature or at 350 °C. Steel coupons were oxidized by heating them at different temperatures. A fast charge-coupled device (CCD) camera captured time-integrated images of the spreading splat. A two-color pyrometer collected thermal radiation from particles and recorded the evolution of their temperature after impact. Molten nickel particles impacting on oxidized steel at room temperature fragmented significantly, while heating the surfaces produced splats with disk-like morphologies. Impact on steel that was highly oxidized induced the formation of finger-like splash projections at the splat periphery. Thermal contact resistance between splats and non-heated oxidized steel was calculated from splat cooling rates and found to decrease as the degree of oxidation increased. On heated, oxidized steel thermal contact resistance was much lower and did not change significantly with the degree of oxidation. It was concluded that thermal contact resistance was largely influenced by adsorbates on the steel surface that evaporated when the surface was heated or oxidized.
Journal: Surface and Coatings Technology - Volume 202, Issue 1, 15 November 2007, Pages 23–33