Adhesion strength of paraffin droplet impacted and solidified on metal substrate
Adhesion strength of paraffin droplet impacted and solidified on metal substrate
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DOI：
10.1016/j.rinp.2022.105310
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发表时间：
2022-02
影响因子：
5.3
通讯作者：
Chao Kang;M. Sakaguchi;Akito Saito;H. Inoue
中科院分区：
文献类型：
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作者：
Chao Kang;M. Sakaguchi;Akito Saito;H. Inoue
热喷涂层中固化层片的脱粘是一个关键问题，它对工业构件的性能和寿命有很大影响。本研究的目的是提供一个深入的了解影响的冲击参数，以及残余应力的剥离行为，以及相关的粘附强度和驱动力的单splats。在这项研究中，熔融石蜡液滴的冲击和固化在不锈钢基板上的剥离行为进行了观察，考虑到基板的预设温度，下降的高度（冲击速度），和液滴温度的影响。结果发现，剥离是容易发生在较低的基板预设温度，较低的下降高度，和较低的液滴温度。然后采用刮擦法来测量在各种条件下形成的飞溅的粘附强度。结果表明，与跌落冲击试验中的脱粘行为有较好的一致性。刮削试验还表明，在刮削过程中，碎片中的残余拉应力降低刮削力，并阻止碎片的完全去除。剥离应力和剪切应力沿着的飞溅-基板界面，这是剥离的驱动力，使用耦合的热力学有限元分析计算。在较低的液滴高度和较低的液滴温度下，剥离更容易发生，计算的驱动力较大。数值模拟和刮削试验的结果为观察到的单个板片脱粘行为提供了合理的解释。本研究提供了一个全面的理解的影响，几个液滴的冲击变量和残余应力的剥离行为，以及相关的粘附强度，以及驱动力的单个飞溅。
Debonding of solidified splats is a crucial issue for thermal sprayed coatings, which greatly influences the performance and lifetime of industrial components. The purpose of this study is to provide an in-depth understanding of the effects of impact parameters as well as residual stress on the debonding behaviors, and the related adhesion strength and driving forces of single splats. In this study, debonding behaviors of molten paraffin droplets which were impacted and solidified on stainless steel substrates, were observed considering the effects of substrate pre-set temperature, drop height (impact velocity), and droplet temperature. It was found that the debonding is prone to take place at lower substrate pre-set temperatures, lower drop heights, and lower droplet temperatures. A scraping method was then employed to measure the adhesion strength of splats formed under various conditions. The results showed good accordance with debonding behaviors in the drop impact test. The scraping tests also indicated that the residual tensile stress in splats reduces the scraping forces and prevents the complete removal of splats during the scraping processes. Peeling stress and shear stress along the splat-substrate interface, which are driving forces for debonding, were calculated using coupled thermomechanical finite element analyses. The calculated driving forces were larger for lower drop heights and lower droplet temperatures under which the debonding was more easily to occur. The results of numerical simulations coupled with scraping tests provide reasonable explanations for observed debonding behaviors of single splats. This study provides a comprehensive understanding of the effects of several droplet impact variables and residual stress on the debonding behaviors, and the related adhesion strength as well as driving forces of single splats.