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采用真空阴极电弧沉积技术在TC11钛合金基体上沉积约10μm厚的Ti/Ti N/Zr/Zr N多层膜,通过对比镀膜前后试样的屈服强度、抗拉强度、疲劳强度、疲劳寿命,以及断口形貌,研究沉积Ti/Ti N/Zr/Zr N多层膜对基体疲劳性能的影响,探讨疲劳断裂机理。结果表明:多层膜对TC11钛合金基体材料的屈服强度和抗拉强度影响不大,但由于膜层硬而脆而降低了基体材料的收缩率和延伸率;多层膜提高基体材料的疲劳极限;低应力下,裂纹源在多层膜表面萌生,并向内部扩展,在多层结构的膜层界面处受到阻碍,发生偏转,从而提高基体疲劳寿命;高应力下,膜层容易破裂,裂纹源增多,降低基体疲劳寿命;应力水平在520 MPa到650 MPa范围内,疲劳寿命增量从+40.82%降到-36.88%。
The Ti / Ti N / Zr / Zr N multilayers with a thickness of about 10 μm were deposited on the TC11 titanium alloy substrate by vacuum cathodic arc deposition. By comparing the yield strength, tensile strength, fatigue strength and fatigue life of the samples before and after coating, As well as the morphology of the fracture surface. The influence of Ti / Ti N / Zr / Zr N multilayers on the fatigue properties of the matrix was investigated, and the mechanism of fatigue fracture was discussed. The results show that the multilayer film has little effect on the yield strength and tensile strength of the TC11 titanium alloy substrate, but reduces the shrinkage and elongation of the matrix due to the hardness and brittleness of the film. The multilayer film improves the fatigue of the matrix material Under the condition of low stress, cracks originated on the surface of multi-layer film and expanded to the interior, which hindered and delaminated at the layer interface of the multi-layer structure to improve the fatigue life of the matrix. Under high stress, the film was easily ruptured, The crack sources increase and the fatigue life of the matrix decreases. The stress level decreases from 520 MPa to 650 MPa and the fatigue life decreases from + 40.82% to -36.88%.