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

即使固体表面看起来非常平坦和光滑，在微观上它也是粗糙的，在微观和纳米尺度上表面有凹凸不平。这些凹凸不平会导致表面的不平整和粗糙度，从而影响界面行为，例如在低摩擦表面，门吱吱作响和刹车声音。当两个接触面相对运动时，摩擦力是由接触颗粒的附着和变形产生的。这对启动接触面滑动所需的载荷有重大影响，包括接触面产生的密封质量。表征表面凹凸不平对粘附力的影响，包括其向动态摩擦的转变，对于开发汽车门闩部件至关重要，这可以减少打开和关闭车门所需的力，包括通过接触面提供的密封性增加而创造更安静的客舱。麦格纳集团（Magna International Inc.）是加拿大一家全球汽车零部件供应商，总部位于安大略省新市场，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。麦格纳正在开发新的汽车闩锁部件，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。该项目将提供关键的摩擦力实验数据，包括表面粗糙度对汽车锁存件的粘附力、粘附力的影响以及它们向动态摩擦的转变。

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.