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NEWS                                                                                                                                                                                                   METALWORKING EQUIPMENT
                                                                                                                                                                                                               AND TOOLS
        Labor chervontsy went into series                                                                                        Spark plasma sintering of tool



                                                                                                                                 materials


               At the initiative of the Ural trade unions, a metallurgist was immortalized on
        coins                                                                                                                           When blade machining of difficult-to-machine steels
               The first commemorative coin from the ''Man of Labor'' series was put into circulation by                         and alloys, the problem arises of choosing a tool material
        the Bank of Russia.                                                                                                      (TM) with an improved composition, taking into account
                                                                                                                                 the peculiarities of the cutting process. One of the most
        The 10-ruble starter coin is dedicated to metallurgy workers.                                                            important indicators of TM in this case is the increased
               ''My colleagues and I pushed this idea for six years, and now it has been implemented.                            heat resistance, which in modern mechanical engineering
        In  total,  according  to  the  idea,  there  will  be  ten  coins  with  ten  professions'',  said  Andrey              is achieved by applying a multifunctional nanostructured
        Vetluzhskikh, deputy of the State Duma of the Russian Federation, chairman of the Federation                             wear-resistant coating on a substrate with increased heat
        of Trade Unions of the Sverdlovsk Region.                                                                                resistance.
               In 2014, at the congress of the interregional public movement ''In Defense of the Working                                The practice of producing products from difficult-to-
        Man'', employees of the Magnitogorsk Iron and Steel Works offered to issue commemorative                                 machine materials has shown that their workability increases
        coins depicting representatives of working professions. The first sketches were created within                           when nanocrystalline composites are used as TM, which include
        a year, and a vote on the choice of professions took place. However, the idea was implemented
        only now.                                                                                                                grains of the nanometric size range.
                                                                                                                                 One  of  the  methods  to  ensure  the          Upper electrode
                                                                                                                                 preservation  of  the  primary  grain               punch
                                                                                                                                 size  of  the  sintered  powder  is  the                                                          SPS-press
                                                                                                                                 use of spark plasma sintering (SPS).
                                                                                                                                 The equipment diagram for the SPS
                                                                                                                                 process is shown in Fig. 1
                                                                                                                                        It  includes a  module  with a                                  Upper punch
                                                                                                                                 vertical  uniaxial  SPS  press  and  a
                                                                                                                                 water-cooled production module;                                         Sintering matrix  SPS - pulse DC generator  SPS - controller
                                                                                                                                 special mechanism that allows current              Vacuum and water cooling chamber  Powder
                                                                                                                                 to pass; a  vacuum  chamber  cooled                                    Lower punch
                                                                                                                                 with water;  controller  of  pressure                                Lower electrode punch
                                                                                                                                 and composition of the atmosphere;                                                                  Positioning
                                                                                                                                 vacuum unit; special D.C. generator                                                          Operating mode (vacuum, air
                                                                                                                                 for  sintering  and  current  pulse                                                                and argon)
                                                                                                                                 controller.                                                                                       Water cooling
                                                                                                                                        Powder materials  are  placed                                                              Thermometer
                                                                                                                                 between  the  die and the  punches
                                                                                                                                 during sintering in the  chamber.                   Fig. 1. Schematic diagram of the ISP equipment
                                                                                                                                 Electric current  is supplied to  the
                                                                                                                                 punches  through  electrodes  and
               This year, the Central Bank plans to launch another coin of the new series. All ''labor                                                               pressure is applied. When a force P is applied, creating pressure,
        chervontsy'' will be legal means of cash payment on the territory of the Russian Federation and                                                              and the passage of electric current pulses, the temperature in the
        must be accepted at face value without restrictions.                                                                                                           sintering matrix rises to 1000 ... 2500 ° C.
                                                                                                                                                                            The  resulting  ultradispersed  TM  has  a  balanced  ratio  of
                                                                                                                                                                           ''hardness - density - strength'', which has a positive effect on
                                                                                                                                                                             wear resistance under the action of cyclic thermomechanical
                                                                                                                                                                             stresses typical for the processing of heat-resistant alloys.
                                                                                                  Text: Svetlana Dobrynina
                                                                                                                                                                             One of the technological tasks of obtaining ultradispersed
                                                                                                                     rg.ru                                                   TM is to determine the optimal, as low as possible, sintering
                                                                                                                                                                             temperature  in order  to minimize  residual stresses  and
                                                                                                                                                                             shorten the sintering time.
                                                                                                                                                                             To solve this problem,  experiments  were  carried  out to
                                                                                                                                                                          obtain an analogue of VK6 grade hard alloy from a mixture of
                                                                                   CREATE A BETTER FUTURE                                                                WC (94 wt. %%) and Co (6 wt. %%) nanopowders by the SPS

                                                                        TOGETHER WITH OUR CUSTOMERS                                                                    method at temperatures from 1000 to 1500 ° C.
                                                                                                                                                                             Fig. 3 shows a graph of the dependence of the hardness
                                                                                                                                                                     and density of the obtained samples depending on the sintering
                                                                                                                                Fig. 2.Graph of the dependence of the
                                                                                                                                hardness (1) of the samples and their
                                                                                                                                density (2) on the sintering temperature.
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