镀层结合强度的测定

测定镀层和基体之间的结合轻度，可以采用使镀层和基体分离开所需性的力。即结合力来衡量根据ASTM D907: 2008 定义”，结合力是。两个表面依靠界面力力保持界面上各处的键或两者所构成。结合力可能是范德瓦的键合强度已达到程度的一种计量，界面力是由价健力或联锁力或界面的化学结合力。

尔斯力、静电力或镀层与基体界结合强度的方法有很多，但定量测定有一定承评定镀层 与基体金属结合强度的些定性试验方法主要有:摩擦试验法、切制试验法。目前常用的一些定性试验方法主要有：摩擦试验法层的拉力试验等，其中适于锌镀层测定的话，形型以装法、到高试险法加热试验法明极试验法，金牌定的有摩擦抛光法、钢球摩擦滚光法剥离(粘胶法)、划线划格法。

但由于问题的复杂性，到目前为止，还没有一种可以用来直接从涂(镀)层材料及涂(镀)层沉积工艺中导出涂(镀)层/基体结合强度的通用理论模型。实际上，目前通行的方法是通过试验来进行定性测定。为了使测定结果更接近实际，应设计出逼近实际情况的试验模型并进行合理的简化以建立正确的计算公式。但是，这在实际中并不总是那么容易做到。原因主要来自于两个方面:一是所设计的试验模型可能不合理，不能正确地代表所研究的实际问题;二是对所设计的试验体系的力学响应不十分清楚，从而采用了不恰当的计算模型。因此，关于镀层结合强度的半定量、定量测量直是表面工程领域研究的难点和热点，近几年来人们对此进行了大量的研究。例如，张全成采用压痕试验法，通过界面在承受压载时的受力分析，建立数学模型，计算出镀层与基体界面的结合强度[41。T. H. Van Steenkiste等采用拉力试验机研究了冷喷涂铝层的结合强度[53)，发现拉伸破坏发生在镀层内部，而没有发生在镀层和基体的结合处;并将涂层的应力-应变曲线与铝块体材料进行了对比，发现涂层拉伸时弹性模量不及铝块体标样的一半; 据此，T. H. Van Stenkisle详细分析了冷喷涂铝层的结合机理。

However, due to the complexity of the problem, up to now, there is no general theoretical model that can be used to directly derive the bonding strength between coating (plating) layer and substrate from coating (plating) material and coating (plating) layer deposition process. In fact, the current method of qualitative determination is through experiments. In order to make the measured results closer to the actual situation, a test model approaching the actual situation should be designed and rationally simplified to establish a correct calculation formula. However, this is not always easy to do in practice. The reasons mainly come from two aspects: one is that the designed test model may not be reasonable and can not correctly represent the actual problems studied; the other is that the mechanical response of the designed test system is not very clear, so an inappropriate calculation model is adopted. Therefore, the semi-quantitative and quantitative measurement of coating bonding strength is a difficult and hot topic in the field of surface engineering. In recent years, a lot of research has been done on it. For example, Zhang Quansheng used indentation test method to establish a mathematical model through the stress analysis of the interface under ballast, and calculated the bonding strength between the coating and the matrix interface [41]. T. H. Van Steenkiste et al. studied the bonding strength of Cold Sprayed aluminium coating by tension testing machine. It was found that the tensile failure occurred inside the coating, but not at the interface between the coating and the matrix. The stress-strain curve of the coating was compared with that of the aluminium bulk material, and it was found that the elastic modulus of the coating was less than half of that of the aluminium bulk sample in tension. Accordingly, T. H. Van Stenkisle was detailed. The bonding mechanism of Cold Sprayed aluminium coating was analyzed.

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