• MATERIALS

    Effects of various fire retardants on mechanical and fire properties of plywood

    Machines. Technologies. Materials., Vol. 14 (2020), Issue 7, pg(s) 292-295

    Effects of various fire retardant (FR) chemicals on mechanical and fire properties of plywoods were investigated. Boron compounds such as, borax and boric acid; and phospate compounds such as, monoammonium phosphate and diammonium phospahate were used as fire retardant chemicals in the plywood panels. An exterior liquid phenol formaldehyde resin with 47% solids content was used as adhesive. The 2.2 mm thick Tetraberlina wood veneers were treated with the liquid solution of FR chemicals. The plywoods having 5-layers were produced from the treated wood veneers. The mechanical properties of the plywoods produced with treated veneers was found to be lower than that of the control group. Among the treated plywoods, The plywoods treated with borax had highest mechanical properties, followed by diammonium phosphate (DAP), monoammonimum phosphate (MAP), and, boric acid, respectively. The FR chemicals improved the fire resistance of the plywoods. The chemicals showed individually different effects related to improvement of fire resistance of the panels. For example, the OSB panels treated with diammonium phoshate were the latest ignited group (52.8 s) which were followed by the panels treated with boric acid (49.2 s), borax (44.5 s), and monoammonium phosphate (41.2 s), respectively. As compared to the control group (7.5 cm), the plywoods treated with borax (3.6 cm) had the shortest flame length after burner was turn off, followed by diammonium phosphate (4.2 cm), boric acid (5.1 cm), and monoammonium phosphate (5.8 cm).

  • TECHNOLOGIES

    Stress-strain state of workpiece from Cu-Cr alloy processed by severe plastic deformation by ECAP

    Machines. Technologies. Materials., Vol. 14 (2020), Issue 6, pg(s) 237-239

    The aim of this work is to study the stress-strain state and thermal effect in a workpiece from low-alloyed Cu-0.6Cr bronze under conditions of intense plastic deformation by equal-channel angular pressing (ECAP). To do this, physical modeling of the sedimentation of the samples was carried out on a Gleeble 3500 installation at temperatures of 20, 400, and 800 ° C and strain rates of 3, 30, and 300 mm / s. Based on the data obtained, a computer simulation of the process of ECAP was carried out in the Deform 3D software package. As a result, the fields of stress distribution, deformation, temperature (deformation heating) and power characteristics of the ECAP process are obtained, depending on various initial temperature and speed conditions.