Different criteria may be used to probe the failure point in the
scratch test. The point of failure may be defined as the onset of microcracking, crazing, fish-scale formation, ploughing, or the point at which the coating is penetrated, revealing the underlying substrate [27].
Nine PP systems were synthesized to investigate the coupling effect of elastic modulus and yield strength on the scratch behavior of PP using an integrated approach of
scratch test and finite element simulation.
There was a significant change in back
scratch test between the pre-test and the post-test on strength assessment day in both CycSG and SSG (p=0.002 and p=0.009, respectively).
Later investigators expanded upon the
scratch test to include not only more sophisticated instrumentation for controlling the load program of the stylus and advanced microscopy for observing the scratch track but also coupling of the scratch method with acoustic spectroscopy whereby the sound vibrations generated by the stylus are detected and recorded at the same time that the scratch track Is being formed.
Scratch test was performed with a scratch-tester (CSM Instruments, Switzerland) which was equipped with Rockwell HRC penetrator with the tip of 120[degrees] cone angle and 100-[micro]m radius.
In addition, the experimental data confirmed how the coatings became progressively stiffer (i.e., progressively higher percentage of plastic contribution) and more brittle (i.e., progressively higher percentage of fracture contribution) when higher sliding speed was set during the constant load
scratch test.
The inferior Apley's
scratch test improved somewhat from the 20 cm pre-treatment discrepancy to a 14 cm post-treatment discrepancy.
Paruchuru, X.Wang, 3D Finite Element Simulation of a Novel
Scratch Test for Assessing the Bone Quality, in Proceedings of BioMedical Engineering Society Annual Fall Meeting, Chicago, Illinois, USA.
To investigate the boundary strength of the printed paperboard, two pattern paperboards were prepared for the
scratch test. One was conventional coated paperboard of 230 g/[m.sup.2] nominal basis weight and 0.3 mm thickness.
RockTron notes that in
scratch test plaques where a PP copolymer containing 15% talc was compared with an identical copolymer with 15% MinTron replacing the talc, "in addition to the vastly improved scratch resistance of the MinTron-filled plaque compared with the talc, a 50% reduction in emissions was measured." Further, the company says, the 20% lower density of MinTron compared with talc means that "if MinTron is substituted on an equal volume basis, then lower-weight components can be produced."
