A high pressure/temperature device for carrying out the synthesis of superhard materials, such as diamond and cubic boron nitride, the device consisting of two dies having recesses in closing faces, said recesses forming, in combination, a high-pressure chamber which accommodates a container charged with a reaction mixture. In each die, the recess is made in the form of a truncated cone conjugated with a sphere or in the form of a hyperboloid of revolution.
Two dies interconnected along the periphery thereof are provided on their oppositely adjacent face surfaces with center recesses and ridges, the latter being disposed coaxially in relation to said recesses. When the dies are drawn together said recesses are adapted to form a high pressure chamber in which a container made of a thermal and electrical insulating material which is ductile under omnidirectional compression is enclosed whereas the ridges are adapted to form concentric circular compartments with the clearances in the joints thereof successively increasing towards the periphery of the dies. The volumes of said compartments also increase from the center towards the periphery of the dies. These compartments are locking in their function and ensure a smooth reduction of pressure exerted by the ductile material on the face surfaces toward the periphery of the dies.
An apparatus for producing high pressure comprises a multi-die system (1). Each die (2) is made up of two cooperating parts arranged along a longitudinal centerline (3) of the die (2), one part being a working body (4), the other being a base member (8). The working body (4) is also made up of two parts in the direction essentially perpendicular to the longitudinal centerline (3) of the die (2), the parts being a central insert (21) and an encircling ring (22) both arranged coaxially and capable of relative displacement towards a test sample (7). The surface area of an end (23) of the central insert (21) of the working body (4) approximates to or less (in this case less) than the surface area of the central portion (18) of an end (11) of the working body (4). An end (5) of the working body (4) is arranged for direct cooperation with a solid medium (6) which is plastic under pressure and serves to surround a sample (7) being tested. An end (9) of the base member (8) faces a die driving means (10) common to all dies. The space between other opposing ends (11 and 12) of the working body (4) and the base member (8) is filled with a solid medium (13) plastic under pressure. The surfaces of the ends (11) and (12) are provided with identical annular grooves (14 and 15) respectively, the grooves being filled with a solid medium (20) plastic under pressure.
Disclosed is a high-pressure generation apparatus, which comprises a pair of columnar-shaped anvils disposed in opposed relation to one another to define a pressure-generating space therebetween. The anvils are adapted to be applied with a load therebetween to generate a high pressure in the pressure-generating space. Each of the anvils has a top portion formed in an approximately circular truncated cone shape, and the top portion has a central region formed with a depression having a side surface which extends obliquely outward. The high-pressure generation apparatus also includes a cylindrical capsule disposed in a central area of the pressure-generating space, and a laminated member formed by alternately laminating a doughnut-shaped metallic thin plate and a doughnut-shaped insulating member along the outer periphery of the capsule. The improved shape of the depression makes it possible to significantly reduce damages of the components. In addition, the laminated member formed of the metallic thin plate and the insulating member originally used for sealing the pressure-generating space makes it possible to generate a higher pressure.
