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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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