Feng Linqian, Benhamida Beatrice Nadia, Lu Chen-Yuan, Sung Li Piin, Morel Pierre, Detwiler Andrew T, Skelly Jon M, Baker Leslie T, Bhattacharya Deepanjan
Eastman Chemical Company, Kingsport, TN, 37662, United States.
Hyundai-Kia America Technical Center, Inc, Superior Township, MI, 48198, United States.
Prog Org Coat. 2018;125. doi: https://doi.org/10.1016/j.porgcoat.2018.09.011.
As original equipment manufacturers (OEMs) strive to deliver improved coating performance with a sustainable footprint, opportunities for innovation are emerging, particularly on improving mechanical properties, appearance, and solids content. Resistance to scratch and mar damage is one of the key performance attributes that has been emphasized by both OEMs and consumers to maintain a vehicle's appearance and corrosion resistance over its service lifetime. Fundamental methodologies including instrumented scratch measurements at multiple size scales are used in this work as part of a product development strategy to better understand the scratch and mar behavior of automotive topcoats. This study compares physical properties of several melamin-formaldehyde and isocyanate cured clearcoats over the appropriate basecoats. Micro- and nano-scratch techniques were employed in combination with industry standard method, Amtec-Kistler carwash to identify performance differences under different scratch conditions. Mechanical and viscoelastic properties of the coatings were studied using tensile tests and dynamic mechanical thermal analysis (DMTA) to better understand the failure mechanisms associated with plastic deformation and fracture at different scratch scales. The information gathered from the above testing protocols is used to analyze coating performance in terms of the contact strain, transitions between elastic - plastic behavior, coefficient of friction and stress localization.
随着原始设备制造商（OEM）努力在实现可持续发展的同时提升涂层性能，创新机遇不断涌现，尤其是在改善机械性能、外观和固体含量方面。耐刮擦和擦伤损坏是OEM和消费者都强调的关键性能属性之一，以在车辆的整个使用寿命期间保持其外观和耐腐蚀性。本研究采用包括多尺寸尺度的仪器化划痕测量在内的基本方法，作为产品开发策略的一部分，以更好地了解汽车面漆的刮擦和擦伤行为。本研究比较了几种三聚氰胺 - 甲醛和异氰酸酯固化清漆在合适底漆上的物理性能。将微观和纳米划痕技术与行业标准方法Amtec - Kistler洗车法相结合，以识别不同划痕条件下的性能差异。使用拉伸试验和动态机械热分析（DMTA）研究涂层的机械和粘弹性性能，以更好地理解在不同划痕尺度下与塑性变形和断裂相关的失效机制。从上述测试方案中收集的信息用于根据接触应变、弹塑性行为转变、摩擦系数和应力局部化来分析涂层性能。
