a1 Department of Civil and Environmental Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139
a2 CSM Instruments, Needham, Massachusetts 02494
a3 Department of Civil and Environmental Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139
This article presents a novel microscratch technique for the determination of the fracture toughness of materials from scratch data. While acoustic emission and optical imaging devices provide quantitative evidence of fracture processes during scratch tests, the technique proposed here provides a quantitative means to assess the fracture toughness from the recorded forces and depth of penetration. We apply the proposed method to a large range of materials, from soft (polymers) to hard (metal), spanning fracture toughness values over more than two orders of magnitude. The fracture toughness values so obtained are in excellent agreement with toughness values obtained for the same materials by conventional fracture tests. The fact that the proposed microscratch technique is highly reproducible, almost nondestructive, and requires only small material volumes makes this technique a powerful tool for the assessment of fracture properties for microscale materials science and engineering applications.
(Received July 28 2011)
(Accepted October 27 2011)
(Online publication January 03 2012)