A method of producing ultrafine-grained materials and a system for mass production of ultrafine-grained materials is disclosed. The system includes a die assembly with a die channel that extends from a first end to a second end. The system also includes first punch and a second punch. A lubricant is poured into a portion of the die channel to surround a workpiece that is positioned within the die channel in order to minimize the effects of friction during processing.

The embodiments herein provide a hydrostatic backward extrusion system that utilizes hydrostatic pressure to produce products with desired cross sectional profile based on backward extrusion process. The system comprises a container, a plunger, fixed-punch, and a billet chamber. The billet material is placed inside the billet chamber. The empty space between the billet chamber and the billet material is filled with a high pressure fluid. Sealing is done at appropriate places to prevent leakage of fluid during the extrusion process. The plunger is moved down to create pressure on the fluid. Due to hydrostatic pressure, the billet material flows into the annular space between the container and the fix-punch. The design of head profile, inner and outer radius of fix-punch allows the billet material to flow smoothly into the annular and forms an extruded product.

A tungsten-base alloy material and a preparation method therefor. The preparation method comprises: 1) evenly grinding composite powder containing tungsten and zirconium oxide, and then performing annealing treatment at 700-1000 C. to obtain powder A; and 2) grinding and then compression moulding the powder A, and then performing liquid-phase sintering to obtain a tungsten-base alloy blank so as to obtain the tungsten-base alloy material.

There are provided: a seamless steel pipe formed from a cylindrical steel material billet through a hot isostatic extrusion step, wherein a depth of a contiguous flaw formed on an inner periphery surface and an outer periphery surface of the steel pipe is 50 m or less; a hollow spring obtained by forming a hollow body in a shape of a coil or a bar or a bar with curved part from the seamless steel pipe made of spring steel and applying a surface treatment to the hollow body so that the hollow body has compressive residual stress; and a method for producing seamless steel pipe including: a billet molding step; a first heating step; a hot isostatic extrusion step; a second heating step; an extension step; a third heating step; and a pickling step.

A system and method for producing a seamless pipe from a hollow billet with a smaller diameter than the seamless pipe, uses a pressure container configured to house the hollow billet. The hollow billet is surrounded by a fluid. A movable punch arranged to fit inside the hollow billet, wherein a hydraulic pressure is transferred from the fluid to the movable punch and to the hollow billet simultaneously, along at least a partial length of the hollow billet. A die opening is arranged serial to the pressure container, wherein the die opening is configured to house a fixed mandrel, the fixed mandrel having a diameter larger than an inner diameter of the hollow billet, so that a gap is formed between the die opening and the fixed mandrel, and the hydraulic pressure of the fluid is generated by an input force from an input punch to move the hollow billet towards the die opening and force the hollow billet material into the gap between the die opening and the fixed mandrel.