Polymer fracture and deformation during nanosectioning in an ultramicrotome. (September 2017)

• Record Type: Journal Article
• Authors: Sun, Fengzhen; Li, Hu; Lindberg, Henrik; Leifer, Klaus; Gamstedt, E. Kristofer
• Is Part Of: Engineering fracture mechanics. Volume 182(2017)
• Page Start: 595
• Page End: 606
• Publication Date: 2017-09
• Subjects: Nanosectioning -- Fracture -- Localized deformation -- Periodic features -- Adiabatic shearing; Fracture mechanics -- Periodicals; Rupture, Mécanique de la -- Périodiques; Fracture mechanics; Periodicals; 620.112605
• DOI: 10.1016/j.engfracmech.2017.05.044
• Languages: English
• ISSNs: 0013-7944

Abstract

Graphical abstract: Highlights: An instrumented ultramicrotome was used to investigate polymer nanosectioning. The fracture toughness for polymers in nanosectioning was in the order of 1–10 J m −2 . Above a threshold thickness, periodic shear bands were formed on the sectioned surfaces. Abstract: The fracture and deformation behaviour of a thermoplastic in the nanosectioning process is investigated by using an ultramicrotome instrumented with force transducers. For sections with thickness values in the order of 10–100 nm, the specific work of surface formation of polymethyl methacrylate is found to be 6.3 J m −2, which is considerably smaller to macroscopic fracture toughness, but relatively close to the theoretical specific surface energy of 1.5 J m −2 of breaking the covalent bonds. Periodic transverse features, spaced a few hundred nanometres on the sectioned surfaces, are observed by atomic force microscopy for sections above a critical thickness. It reveals that a transition of the deformation mode occurs at a certain thickness, which is in concert with sectioning experiments for other materials showing adiabatic shear bands.