Two condensed electron-beam copper coatings, one consisting of copper and the other of Hf/Ag/Ni/Cr microlayers, were deposited onto a titanium alloy (Ti−6Al−4V) substrate to study the energy dissipation and fatigue resistance in the uncoated and coated samples under nonbreaking and breaking cyclic stresses. The microlayer coating is peculiar in that a material with a higher elastic modulus is used in each subsequent layer (from the substrate to the outer layer) and the coating layers and submicron twins in the binder sublayer have a columnar microstructure peculiar to electron-beam evaporation and vacuum condensation. Having layered macro- and microstructure, the coating absorbs the energy of vibrations through both internal friction (between the coating layers and between the coating and substrate) and dissipation of vibration energy on numerous defects in the columnar structure (intercolumnar porosity). Resonant first- and secondmode vibrations were excited in cantilevered samples to determine how the vibration decrement depended on their maximum stresses and the breaking fatigue stresses on the number of load cycles. In addition, vibration transmission coefficients for cyclic stresses and vibration energy were experimentally defined and justified for use. One coefficient is equal to the ratio of difference in stresses between the uncoated and coated samples to stresses in the uncoated sample, relative machine power being the same in various tests. The other coefficient is equal to the ratio of difference in energy between the uncoated and coated samples to the energy of vibrations induced in the uncoated sample, relative machine power being the same in various tests. The Hf/Ag/Ni/Cr coating is shown to provide greater energy dissipation but lower fatigue properties than the Cu coating and substrate. The vibration transmission coefficients are more sensitive to energy dissipation than the vibration decrement is.

中文翻译：

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有效降低涂层样品中的循环应力

两种凝聚电子束铜涂层，一种由铜组成，另一种由 Hf/Ag/Ni/Cr 微层组成，沉积在钛合金 (Ti-6Al-4V) 基材上，以研究未涂层的能量耗散和抗疲劳性和涂层样品在不间断和断裂循环应力下。微层涂层的独特之处在于其后的每一层（从基材到外层）均使用弹性模量较高的材料，并且涂层和粘合剂子层中的亚微米孪晶具有电子束蒸发特有的柱状微观结构和真空冷凝。具有分层的宏观和微观结构，涂层通过内部摩擦（涂层之间以及涂层与基材之间）和振动能量在柱状结构中的许多缺陷（柱间孔隙）上的耗散来吸收振动能量。在悬臂式样品中激发共振一阶和二阶模态振动，以确定振动衰减如何取决于它们的最大应力和断裂疲劳应力对负载循环次数的影响。此外，循环应力和振动能量的振动传递系数是通过实验定义的，并证明可以使用。一个系数等于未涂层样品和涂层样品之间的应力差与未涂层样品的应力之比，相对机器功率在各种测试中相同。另一个系数等于未涂层和涂层样品之间的能量差与未涂层样品中引起的振动能量之比，相对机器功率在各种测试中相同。与 Cu 涂层和基材相比，Hf/Ag/Ni/Cr 涂层显示出更大的能量耗散，但疲劳性能更低。与振动衰减相比，振动传递系数对能量耗散更敏感。