材料期刊网

多层结构可以提高材料的强度、弹性模量和韧性。当尺寸减小到纳米量级时，性能将产生飞跃变化。首先探讨了多层结构提高强度、弹性模量和韧性等性能的基本原理，然后阐明了纳米尺度效应及理论，重点以过渡族金属氮化物ZrN纳米多层膜为例，研究了氮化物／金属（ZrN／Cu）纳米多层膜、ZrAIN纳米复合膜以及ZrAIN／Cu纳米多层膜的强韧化性能。结果表明，ZrN／Cu纳米多层膜的断裂韧性约是二元ZrN薄膜的2倍。当纳米多层膜的Cu单层厚度为2013131时，多层膜的K1C值最高。ZrAIN复合膜的断裂韧性与Al含量密切相关，当Al原子分数为23％时，薄膜的KIc值达3．17MPa·m^1/2，其硬度〉40Gpa，Al原子分数为47％的薄膜的K1C值则降低到1．13MPa·m…。，其硬度降低至17．1GPa。与z州／cu纳米多层膜和ZrAlN复合膜相比，以ZrAIN层和cu层为调制结构制备的ZrAlN／Cu纳米多层膜具有最高的硬度和最好的韧性。

Muhilayer film can improve the strength, elastic modulus and toughness of materials markedly, the perform- ance of film will be significantly improved if multilayer period is reduced to nanometer scale. This paper studied the tough- ening and strengthening of ZrN/Cu nano-muhilayer film, ZrA1N composited film and ZrAIN/Cu nano-multilayer film, the morphology of films were investigated by FESEM, the microstructure was studied by XRD, XPS and TEM. The plastic deformation characteristic of thin films were analyzed from loading/unloading curves measured by nano-indentation meth- od. The results show that： the fracture toughness（K1C） of ZrN/Cu is 2 times that of ZrN film. ZrN/Cu has the maximum Kic value when Cu mono-layer thickness is 20 nm. For ZrA1N composite film with 23% AI（ atomic percent） , the Klc is 3.17 MPa ·m1/2, hardness is greater than 40 GPa, while for ZrA1N with 47% AI（ atomic percent） , the Kjc is 1. 13 MPa · m1/2 , hardness is 17. 1 GPa. ZrAIN with 23% Al（atomic percent） is more ＂hard and tough＂ than ZrAIN with 47% Al （atomic percent） , showing its properties are remarkly affected by A1 raito in composite film. ZrAIN/Cu nano-muhilayer film has best hardness and toughness compared with ZrN/Cu nano-multilayer film and ZrA1N composited film.