For low prediction precision of online model for vertical rolling force in roughing trains of hot strip mill, the process of hot strip roughing trains was simulated by the FEM simulation software DEFORM. The cause of low prediction precision of rolling force during vertical rolling was analyzed. Then the new method for calculating deformation degree when edge rolling was presented by analysis of the FEM simulated results. The formula of external stress status modulus, which is fit for the vertical rolling force calculation, was obtained by analytic regression. Furthermore, a new formula about rolling force calculation was gained. It was approved that the prediction precision was obviously enhanced compared with the practical data for vertical rolling force.
Cutting tools of WC-Co are widely used in cutting field. Nevertheless, its wear resistance and lifetime are not qualified for the high performance cutting. Therefore, diamond films are deposited on WC-Co substrates to overcome its disadvantages. In this paper we investigate the effects of the pretreatment on substrates and as-deposited WC-Co samples by using a hot filament chemical vapor deposition (HFCVD) reactor. Prior to deposition, the WC-Co substrates were submitted to surface roughening by Murakami reagent and to surface binder removal by Caro’ acid with varied durations. Surface roughness Ra determined by AFM varied from 110 to 279 nm. The diamond films are characterized by scanning electron microscopy (SEM) and Raman spectroscopy, whose results present a sharp peak at 1336 cm-1 indicating sp3 diamond. The adhesion between the diamond films and substrates was evaluated by pull-off tests with the highest adhesion strength is 26.92 MPa. Cracked interface is characterized between diamond films and substrates, using SEM and energy dispersive spectroscopy (EDS) to analyze the adhesion performance.
A nanotwinned surface is formed on a titanium alloy under nanoindentations. Prior to nanoindentation, blocks of a ternary titanium alloy are machined by chemical mechanical polishing. The surface roughness Ra and peak-to-valley values are 1.135 nm and 8.82 nm, respectively. The hardness in the indented surface is greatly increased, indicated from the load-displacement curves compared to the polished surfaces. Nanotwins are confirmed using transmission electron microscopy. The nanotwinned surface is uniformly generated by nanoindentations at room temperature, which is different from previous findings, in which high temperature, high pressure, or chemical reagents are usually used. The nanotwinned surface is produced by pure mechanical stress, neither material removal nor addition.
In this study, a long stroke atomic force microscope (LS-AFM) has been developed for the measurement of the micro-optics which have micrometric amplitude surface structures. An electrochemically polished tungsten wire is used as the AFM probe tip. Since the effective length of the tungsten probe is more than 100 μm, the probe tip can access valley part without the interference between the steep slope and the sidewall of the probe tip. By using the long stroke PZT Z scanner whose long stroke of 70 μm and a resolution of 1 nm, micrometric amplitude of the optical elements can be measured. A linear encoder is employed to measure the displacement of Z scanner in Z direction. A well-detected result of a prism sheet film profile has been obtained by the LS-AFM and its tapping mode.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.