Abstract: The present invention relates to a tube member having excellent local bending properties that is capable of being freely bent only on a given region thereof at a working temperature, thereby enabling the bending angle thereof to be freely adjusted by a user, and a method for manufacturing the tube member. According to the present invention, the tube member having excellent local bending properties, which is made of an alloy, may include a first region and a second region having different alloy structures from each other. According to the present invention, the first region may be in a cold-worked state or have an austenite phase at a given working temperature, and the second region may have a martensite phase at the given working temperature and a yield stress value lower than a yield stress value of the first region.

Abstract: A method of safely stabilizing carbon nanotubes containing reactive or unstable catalyst metal particles by selective oxidation, or melting and removing the catalyst metal particles under controlled conditions. In one embodiment, the method may include preparing carbon nanotubes containing a residual catalyst metal, pickling the carbon nanotubes, and the subsequence oxidation of the residual catalyst metal by heat-treating without oxidation of the carbon nanotubes. In another embodiment, the method may include preparing carbon nanotubes containing a residual catalyst metal, first acid pickling, melting the residual catalyst metal by heat-treating in a vacuum chamber, and second acid pickling to remove the melted residual catalyst metal.

Abstract: The present invention has been proposed to solve various problems including the above problems, and an object of the present invention is to provide a method of stabilizing carbon nanotubes by oxidizing catalyst metal particles included in the carbon nanotubes by oxidation heat treatment or by melting and removing the catalyst metal particles in a vacuum atmosphere. According to an aspect of the present invention to achieve the object, the method includes preparing carbon nanotubes including a catalyst metal and oxidizing the catalyst metal by heat-treating the carbon nanotubes. According to another aspect of the present invention to achieve the object, the method includes preparing carbon nanotubes including a catalyst metal, melting the catalyst metal by heat-treating the carbon nanotubes, and acid pickling the carbon nanotubes having undergone the melting process.

Abstract: According to one aspect of the present invention, a method of producing a particle-shaped diamond single-crystal using chemical vapor deposition (CVD). According to one embodiment, the method includes disposing a single-crystal diamond grit seed on a stage substrate in a diamond synthesis chamber and three-dimensionally growing the single-crystal diamond grit seed to a particle-shaped diamond single-crystal by introducing a source gas into the chamber.

Abstract: The present disclosure relates to a screw coupling structure for preventing loosening, and more particularly, to a screw coupling structure for preventing loosening for preventing loosening between a screw portion and an engagement portion, which includes the screw portion having a predetermined length and the engagement portion having a screw hole through which the screw portion is inserted and engaged, in which the screw portion is formed of a shape memory alloy deformable by an external force applied thereto at a temperature lower than a predetermined threshold temperature and recoverable from the deformation by heating to a temperature higher than the threshold temperature.

Abstract: A shape memory alloy (SMA) actuator. The SMA actuator, which generates an operating force by using SMA elements, includes fixed member, movable member mounted on fixed member to move between first position and second position, first SMA element mounted to positionally move the movable member to the first position, a second SMA element mounted to positionally move the movable member to second position, a first position fixing means for positionally fixing the movable member at the first position by a magnetic force in such a way that the movable member is separable from first position fixing means, and second position fixing means for positionally fixing the movable member at the second position by a magnetic force in such a way that the movable member is separable from the second position fixing means. According to the present invention, a high reaction speed and remarkably reduced power consumption can be provided.

Abstract: A connecting device using a shape memory alloy (SMA). The connecting device uses an SMA, which firmly connects female member with male member inserted into the female member, in which a wire member formed of an SMA material is wound a plurality of times in a spiral shape, a hollow into which the female member is inserted is formed in a center portion of the spiral shape, and when the male member being inserted into the female member, the wire member presses against an outer circumferential surface of the female member to prevent the male member from being separated from the female member. According to the present invention, a connection is possible in a high-temperature phase corresponding to room temperature as well as in a low-temperature phase, and an allowable tolerance, which is a difference between a diameter of a hollow and an outer diameter of a female member, increases.

Abstract: A shape memory alloy (SMA) actuator. The SMA actuator, which generates an operating force by using SMA elements, includes fixed member, movable member mounted on fixed member to move between first position and second position, first SMA element mounted to positionally move the movable member to the first position, a second SMA element mounted to positionally move the movable member to second position, a first position fixing means for positionally fixing the movable member at the first position by a magnetic force in such a way that the movable member is separable from first position fixing means, and second position fixing means for positionally fixing the movable member at the second position by a magnetic force in such a way that the movable member is separable from the second position fixing means. According to the present invention, a high reaction speed and remarkably reduced power consumption can be provided.

Abstract: A stent includes: a main body unit including a plurality of through holes and configured to have a net-like shape; and a coating unit filling the through holes of the main body unit and configured as a layer on the main body unit, wherein the main body unit has force of restitution to be restored to its original shape, and the coating unit includes a support unit for maintaining the shape of the main body unit by hampering the restoration of the main body unit and a blocking unit blocking the through holes of the main body unit to discriminate the interior and the exterior of the main body unit. The stent can be quickly expanded in a blood vascular system, or the like, after being inserted into the body in a surgical procedure, thus improving expansion (or extension) effect.

Abstract: A method for enhancing an initial tension by changing a wound direction of a coil spring. A large and precise initial tension is provided to the coil spring. An actuator having an excellent function is prepared by using a shape memory alloy. Each shape of the coil spring at high and low temperatures can be controlled by a flexible shape memory effect.

Abstract: Disclosed is a method for fabricating a composite material comprising nano carbon and metal or ceramic, in more detail, a method for fabricating a composite material in which metallic or ceramic particles are uniformly dispersed on a nano carbon surface, the method including (1) coating a metal layer on nano carbon, (2) fabricating composite nano powders by performing a thermal treatment for the nano carbon coated with the metal layer, and (3) sintering the composite nano powders, whereby the composite nano powders, in which metallic or ceramic nano powders are uniformly mixed on the surface of the nano carbon, can be easily fabricated, and such composite nano powders can be sintered so as to fabricate the composite material, in which the nano carbon and the metallic or ceramic powders are uniformly dispersed.

Abstract: A new shrink fitting method including deformation is disclosed, in which a high bonding force can be obtained without accurate mechanical process such as forming an insertion body having an outer diameter greater than an inner diameter of an object for receiving the insertion body. The shrink fitting method comprises preparing a pipe and a rod material whose inner and outer diameters are different from each other; bonding the pipe and the rod material to each other in a state that the pipe or the rod material is deformed by heating; deforming the pipe to allow the inner diameter of the pipe to be equal to the outer diameter of the rod material; and cooling the bonded pipe and rod material. The shrink fitting method can be widely used for various mechanical parts.

Abstract: The present invention relates to a damping structure which is capable effectively damping vibration of a structure. The damping structure includes a vibration controlling medium fixed at a structure and vibrating with an amplitude greater than that of the structure upon vibration and a damper vibrating separately from the vibration controlling medium as a result of being loosely fitted into the vibration controlling medium or a damper supporter extended therefrom, and thus having a vibration frequency different from that of the vibration controlling medium.

Abstract: Disclosed is a diamond saw capable of reducing noise by installing a damper for absorbing vibration in a shank. The low noise diamond saw comprises: a shank formed of a circular metallic plate; and a diamond blade bonded to an outer circumferential surface of the shank, in which a damper is partially bonded to one or both of upper and lower surfaces of the shank by a spot welding.

Abstract: A method for enhancing an initial tension by changing a wound direction of a coil spring. A large and precise initial tension is provided to the coil spring. An actuator having an excellent function is prepared by using a shape memory alloy. Each shape of the coil spring at high and low temperatures can be controlled by a flexible shape memory effect.

Abstract: A new shrink fitting method including deformation is disclosed, in which a high bonding force can be obtained without accurate mechanical process such as forming an insertion body having an outer diameter greater than an inner diameter of an object for receiving the insertion body. The shrink fitting method comprises preparing a pipe and a rod material whose inner and outer diameters are different from each other; bonding the pipe and the rod material to each other in a state that the pipe or the rod material is deformed by heating; deforming the pipe to allow the inner diameter of the pipe to be equal to the outer diameter of the rod material; and cooling the bonded pipe and rod material. The shrink fitting method can be widely used for various mechanical parts.

Abstract: In a joining method for a frame of spectacles, and in more particular to a method for joining a bridge or a temple to a lens rim, a joining method for a frame of spectacles comprises deforming a joining portion of a member made of a shape memory alloy material so as to be insertable into a pipe for joining the member to a lens rim, and joining the joining portion of the member to the pipe by returning the joining portion of the member to an original shape before the deformation after the member is inserted into the pipe.

Abstract: A multi-layered metal plate with excellent damping capacity and particularly, to a multi-layered metal plate with excellent damping capacity and a method for manufacturing it, is less costly since the plate can be simply manufactured by simply attaching a thin plate on a main metal plate by the methods such as welding and the like, has excellent damping capacity and especially can be easily shaped. In addition, in the plate, the secondary plate is attached on one or both surfaces of the main metal plate.

Abstract: For a pipe joining method using shape memory alloy capable of preventing a shape memory capacity loss due to a pipe's tolerance, a shape memory alloy joint having an inner diameter greater/less than an outer diameter of pipes to be joined is installed at the outer/inner circumference of a pipe joining portion, and the pipes and the shape memory alloy joint are simultaneously enlarged/reduced. In addition, a general metal joint having an inner diameter greater/less than an outer diameter of shape memory alloy pipes to be joined is installed at the outer/inner circumference of a shape memory alloy pipe joining portion, and the shape memory alloy pipes and the general metal joint are simultaneously enlarged/reduced.

Abstract: For a pipe joining method using shape memory alloy capable of preventing a shape memory capacity loss due to a pipe's tolerance, a shape memory alloy joint having an inner diameter greater/less than an outer diameter of pipes to be joined is installed at the outer/inner circumference of a pipe joining portion, and the pipes and the shape memory alloy joint are simultaneously enlarged/reduced. In addition, a general metal joint having an inner diameter greater/less than an outer diameter of shape memory alloy pipes to be joined is installed at the outer/inner circumference of a shape memory alloy pipe joining portion, and the shape memory alloy pipes and the general metal joint are simultaneously enlarged/reduced.