Effects of Asperities on Stiction and Its Transition to Dynamic Friction in Automotive Latch Parts

即使当固体表面看起来非常平坦和光滑时，它在微观上是粗糙的，具有微米和纳米尺度的表面粗糙体。这些凹凸不平导致表面不均匀和粗糙，影响界面行为，如发生在低摩擦表面，吱吱作响的门和刹车声。当两个接触表面相对于彼此移动时，摩擦力由接触凸体的粘附和变形贡献。这对启动接触表面的滑动所需的载荷量具有显著影响，包括由接触表面产生的密封的质量。表征表面粗糙度对静摩擦力和粘附力的影响（包括其向动态摩擦的转变）在开发汽车闩锁部件中是必不可少的，所述汽车闩锁部件减少打开和关闭车门所需的力的量，包括由于接触表面提供的增加的密封而产生更安静的车厢。麦格纳关闭，麦格纳国际公司的部门，是一家加拿大全球汽车供应商，总部位于安大略新市场，是北美最大的汽车零部件制造商，也是加拿大最大的公司之一。麦格纳正在开发新型汽车锁闩部件，以提高车门质量和车厢安静度，这对汽车制造商来说是两个关键的客户满意度考虑因素。该项目将提供摩擦力的关键实验数据，包括表面粗糙度对静摩擦力的影响，粘附力及其向汽车闩锁部件动态摩擦的过渡。

Even when a solid surface looks very flat and smooth, it is rough microscopically with surface asperities in the micro and nanometer scale. These asperities result in unevenness of surfaces and roughness which affects interfacial behaviour such as occurs in low friction surfaces, creaking doors and brake sounds. When two contacting surfaces move relative to each other, frictional force is contributed by adhesion and deformation of the contacting asperities. This has a significant effect on the amount of load needed to initiate sliding of the contacting surfaces including the quality of the seal that is created by the contacting surfaces. Characterizing the effect of surface asperities on stiction and adhesion including its transition to dynamic friction is essential in developing automotive latch parts that reduces the amount of force needed to open and close a car door including creating a quieter cabin as a result of increased sealing provided by the contacting surfaces. Magna Closures, division of Magna International Inc., is a Canadian global automotive supplier headquartered in New Market, Ontario and it is the largest automobile parts manufacturer in North America by sales of original equipment parts, and one of Canada's largest companies. Magna is developing novel automotive latch parts that improves door quality and cabin quietness, which for automakers, are two key customer satisfaction considerations. This project will provide critical experimental data on the frictional forces including the effect of surface asperities on stiction, adhesion and their transition to dynamic friction for the automotive latch parts.