低温沉积Ag-Cu薄膜的耐原子氧和摩擦学性能

Atomic Oxygen Resistant and Wear Behavior of Ag-Cu Films Deposited at a Low Temperature

采用多弧离子镀在低温(173 K)沉积了Ag-Cu薄膜,通过地面原子氧模拟试验机构考察了薄膜的耐原子氧性能,通过X射线衍射(XRD)、原子力显微镜(AFM)和球-盘摩擦试验机对薄膜结构、耐原子氧性能和摩擦学性能进行了表征,并与室温(300 K)及低温(173 K)沉积Ag薄膜进行了比较研究.结果表明:低温沉积Ag-Cu薄膜由面心立方结构的AgCu合金相和少量Ag或Cu组成,Cu元素合金和低温沉积可细化Ag薄膜的晶畴尺寸、提高其致密性,细密的薄膜结构有利于抑制原子氧对薄膜的攻击,因此低温沉积的Ag-Cu薄膜表现出较好的耐原子氧性能;磨损试验结果表明低温沉积的Ag-Cu薄膜表现出较好的耐磨性,这主要归因于其细密的薄膜结构和较高的膜-基结合强度,此外由于其耐原子氧性能的改善,低温沉积Ag-Cu薄膜在原子氧辐照前后磨损率的增加明显低于低温和室温沉积Ag薄膜.

Ag -Cu films were deposited at a low temperature （ 173 K, LT - Ag - Cu films） by arc ion plating. Atomic oxygen （AO） irradiation experiments were conducted using a ground AO simulation facility. The AO resistant and wear behavior of the LT - Ag - Cu films were investigated by X - ray diffraction, atomic force microscope and a ball - on - disk tribometer using Ag film deposited at room temperature （300 K, RT -Ag film） as a reference. The results show that the LT - Ag - Cu films were composed of AgCu alloy and small amount of Ag or Cu. Because of densified microstrueture, lower crystallite size and alloying with Cu, the LT - Ag - Cu film represented much better anti - oxidation capability under the AO irradiation condition than that of the RT - and LT - Ag films. Wear results show that as compared with the RT - Ag film, the LT - Ag - Cu films exhibited much better wear resistance due to the better film - substrate adhesion as well as the fine/ dense structure, and the wear increase resulted from the AO irradiation was much lower for the LT - Ag - Cu films than the RT - and LT- Ag film due to the improvement in the AO resistant behavior.