Subsurface damage (SSD) introduced from abrasive machining significantly degrades the reliability and lifetime of glass ceramics. In this work, nanoindentation tests were performed on the cross section near the lapped surface to determine the nanomechanical properties of subsurface layer of a lapped BK7. Remarkable differences were found between SSD layer and its bulk counterpart in terms of load-displacement characteristics and nanomechanical response. The nanomechanical parameters (hardness and elastic modulus) of subsurface layer follow an exponential descending trend with the shortening of distance from lapped surface, which is consistent with the increase of crack density. The ratio of hardness to elastic modulus decreases exponentially with increasing subsurface depth until it reaches bulk material, which suggests that SSD layer has lower plasticity. Furthermore, the crack distribution becomes a critical parameter for characterizing the hardness gradient in SSD layer.

研磨加工引起的表面下损伤（SSD）大大降低了玻璃陶瓷的可靠性和使用寿命。在这项工作中，对重叠的表面附近的横截面进行了纳米压痕测试，以确定重叠的BK7的次表面层的纳米机械性能。在负载位移特性和纳米力学响应方面，SSD层与其整体对应物之间存在显着差异。表层下层的纳米力学参数（硬度和弹性模量）随着与研磨面距离的缩短而呈指数下降趋势，这与裂纹密度的增加是一致的。硬度与弹性模量之比随表面深度的增加呈指数下降，直到到达块状材料为止。这表明SSD层的可塑性较低。此外，裂纹分布成为表征SSD层中硬度梯度的关键参数。