Influence of contact area on the sliding friction and wear behaviour of an electrochemical jet textured Al-Si alloy
Influence of contact area on the sliding friction and wear behaviour of an electrochemical jet textured Al-Si alloy
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DOI：
10.1016/j.wear.2019.01.008
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发表时间：
2019-04-30
期刊：
影响因子：
5
通讯作者：
Clare, A. T.
中科院分区：
文献类型：
--
作者：
Walker, J. C.;Cinti, S.;Clare, A. T.
环境立法继续推动优化内燃机在汽车行业的努力，以减少有害排放和提高燃油效率。在环组处存在显著的摩擦损失，促使研究人员通过使用表面变形来减少环-衬板界面处的滑动摩擦。本研究评估了接触面积对电化学喷射织构表面产生的轻质整体超共晶Al-Si合金摩擦磨损行为的影响。在1 mol NaOH溶液中浸泡120 s以模拟机械珩磨过程，通过电火花加工制备扁平矩形样品，并将其平研磨至6 μ m金刚石光面。采用2.3 mol NaC1溶液和220 a /cm(2)的电流密度对表面进行电化学喷印。在一个直径6毫米、长13毫米、初始接触压力分别为157、12和4 MPa的52100钢缸中，在100摄氏度的条件下，在冲程长度为25毫米的PAO （4 cSt）浴液中进行了润滑往复滑动。在50 N的载荷下，滑动频率在1到15 Hz之间变化，以确定接触压力和速度对摩擦行为的影响，作为润滑制度的函数。观察到，如果反表面接触宽度大于特征尺寸，则纹理特征可以通过润滑剂储层机制将平均摩擦系数降低37%。由于胶粘剂磨损而不是纹理特征的加压，接触压力的增加防止了微ehl效应。
Environmental legislation continues to drive optimisation of internal combustion engines in the automotive sector in an effort to reduce harmful emissions and promote fuel efficiency. Significant frictional losses occur at the ring pack, prompting research on reducing sliding friction at the ring - liner interface through the use of surface texturing. This study assesses the influence of contact area on the friction and wear behaviour of lightweight monolithic hyper-eutectic Al-Si alloy with a textured surface generated by electrochemical jet texturing. Flat rectangular samples were prepared from a cast cylinder liner via electro-discharge machining and flat lapped to 6 mu m diamond finish prior to immersion in a 1 mol solution of NaOH for 120 s to simulate the mechanical honing process. Surfaces were electrochemically jet textured using a 2.3 mol solution of NaC1 and current density of 220 A/cm(2). An offset array of 1.3 x 0.3 mm rectangular features at 1.2 mm spacing was created with an average depth of 39 mu m. Lubricated reciprocating sliding was carried out at a stroke length of 25 mm in a bath of PAO (4 cSt) at 100 degrees C against a 6 mm diameter, 13 mm long 52100 steel cylinder with three different contact areas corresponding to initial contact pressures of 157, 12 and 4 MPa. Sliding frequencies were varied between 1 and 15 Hz at a load of 50 N in order to establish the influence of both the contact pressure and velocity on the friction behaviour as a function of the lubrication regime. Textured features were observed to reduce the average coefficient of friction by up to 37% via a lubricant reservoir mechanism if the counter-surface contact width was greater than the feature dimension. Increases in contact pressure prevented a micro-EHL effect due to adhesive wear rather than pressurization of textured features.