应用数字图像相关方法测量金刚石工具镀层与基体的结合强度

Measuring the bonding strength between electrodeposited layer and tool substrate with digital-image correlation method

提出一种新的电镀金刚石工具镀层与基体结合强度测试方法。分别制备了亮镍和添加稀土的电镀结合剂镀层。镀层试件经过制斑与加载,经CCD采集成为数字图像,通过数字图像处理系统进行相关性计算,寻找到试件加载变形后的数字图像采集区域,从而计算出采集区域内的位移和应变。通过镀层与基体界面处应变的变化,分析镀层的结合状态。实验结果,镍-镧镀层与基体的结合强度高于亮镍铍层与基体的结合强度。研究结果表明利用数字图像相关方法测量镀层与基体结合强度是一种简单有效的方法。

A new method for measuring bonding strength between eleetroplated layer and substrate of diamond tool is proposed. Electroplated layers with bright nickel and rare earths added-bright nickel were fahricated. Samples of layers were spotted and loaded. Digital images on samples obtained by CCD camera were analyzed with correlation calculation method. Digital image regions before and after loads were identified. Then, the displacement and strain within digital image region were calculated. The bonding strength can be estimated according to the change of strain between layer and substrate. The experimental results suggest that the bonding strength of nickel-lanthanum elcctrodeposits is higher than that of bright nickel. The research results show that digital-image correlation method could provide a simple and effective measuring method for the bonding strength electroplated layer and substrate.