摩擦偶件对单晶硅宏观摩擦磨损行为的影响

Effect of Counterparts on the Friction and Wear Behavior of Single Crystal Silicon

研究了单晶硅分别与Si3N4、红宝石及GCr15钢对摩时的摩擦磨损性能.结果表明:单晶硅与不同偶件对摩时的摩擦系数均随着滑动速度的提高而降低;在相同试验条件下,单晶硅与GCr15钢对摩时的摩擦系数最高,这主要是由于单晶硅与GCr15钢中的过渡金属元素Fe具有很强的化学亲合势所致;而单晶硅与红宝石对摩时的磨损体积损失最大,与GCr15钢对摩时的磨损体积损失最小;低速下Si3N4和红宝石陶瓷偶件与单晶硅对摩时磨损表面存在大量的微断裂,随着滑动速度的增加其磨损表面逐渐变得较为光滑;GCr15钢与单晶硅对摩初期向单晶硅表面转移,在随后的摩擦过程中转移层因磨损而被去除,故单晶硅/GCr15钢磨损表面比其他2种摩擦副的磨损表面光滑.

The friction and wear behaviors of single crystal silicon sliding against different counterparts at ambient air and low contact stress under unlubricated condition within a velocity of 3-90 mm/s were studied using a LTMT-2MT test rig. The morphologies and chemical features of the worn surfaces under various conditions were analyzed by means of scanning electron microscopy. It was found that the counterparts had significant effects on the friction and wear behavior of the single crystal silicon. Namely, single crystal silicon coupled with GCr15 (AISI1045) steel recorded the highest friction coefficient and smallest wear volume loss among the three frictional pairs, while it had the highest wear volume loss as slid against ruby. It was supposed that the high friction coefficient for the GCr15/single crystal silicon pair was ascribed to the strong chemical affinity between the silicon and the transition metal Fe contained in the steel. Moreover, the different wear volume losses of the single crystal silicon sliding against different counterparts could be related to the different wear mechanisms. In other words, the worn surfaces of the silicon were characterized by a large number of micro-fractures when it slid against Si3N4 and ruby, while that of the silicon sliding against the steel showed signs of the steel transfer during the running-in period and some kind polishing effect at the steady-state sliding and the micro-fracturing was restrained. This corresponded to the better wear resistance of the single crystal silicon in coupling with the steel than in coupling with Si3N4 and ruby.