Osaka University

Osaka Municipal Technical Research Institute

Sumitomo Electric Industries, Limited

Toshiba Materials Co., Ltd.

Ntk Cutting Tools Co., Ltd.

Tokyu Car Corporation

Yoshiaki Morisada

Hidetoshi Fujii

Yasuhiro Aoki

Masahiro Kato

Hideki Moriguchi

Yoshiharu Utsumi

Yutaka Abe

Kai Funaki

Isao Ikeda

Hiroki Takeuchi

Yusuke Katsu

Rintaro Ueji

Hiroka Aoyama

Masayoshi Kamai

Takayuki Fukasawa

Masanori Yasuyama

Jun Moteki

Takeshi Ishikawa

Hiroka Miyazaki

Yuki Takeuchi

Gen Murayama

Yasushi Hara

Tomoya Nagira

Kohsaku Ushioda

Huihong Liu

Akihiko Ikuta

Masao Fukusumi

A friction stir welding tool and a friction stir welding method that can increase the amount of heat generation, while reducing the amount of escaping heat are provided. The friction stir welding tool () has a shoulder portion () and a probe portion () provided on a bottom surface of the shoulder portion (). The base material of the friction stir welding tool () is a ceramic material whose main phase is silicon nitride or sialon. The shoulder portion () has a diameter of 35 mm or greater.

Friction stir welding tool and friction stir welding method

The objective of the present invention is to provide a friction pressure welding method with which the welding temperature can be controlled accurately, the welding temperature can be lowered, and the distribution of the welding temperature at an interface to be welded can be made uniform; and to provide a welded structure obtained by this method. The present invention relates to the friction pressure welding method in which one member is abutted against another member and is made to slide in a state in which a welding pressure substantially perpendicular to the interface to be welded is applied, said friction pressure welding method being characterized in that the maximum sliding speed is no greater than 53 mm/sec, the difference in the temperature increase rate between a center portion and an outer peripheral portion at the interface to be welded is 10° C./sec or less, and the difference between the maximum attained temperature between the center portion and the outer peripheral portion at the interface to be welded is no greater than 50° C.

Friction pressure welding method

The present invention provides a weathering steel for solid-state welding that forms an excellent weld when subjected to solid-state welding and has tensile properties equivalent or superior to those of high tensile strength steel, said steel having weathering properties superior to those of conventional weathering steel for welding, wherein the reliability of the weld is equivalent or superior to that of the parent material; and a weathering steel material for solid-state welding. Further, there is provided a solid-state welded structure that includes the weathering steel for solid-state welding according to the present invention, and a solid-state welding method for said weathering steel for solid-state welding. The weathering steel for solid-state welding having a steel composition comprises, in % by mass, C: 0.10 to 0.60% and P: more than 0.035 to 1.000%, with the remainder consisting of Fe and unavoidable impurities.

Weathering steel for solid-state welding, weathering steel material for solid-state welding, solid-state welded structure and solid-state welding method

A friction stir welding tool () has a shoulder portion () and a probe portion () provided on a bottom surface of the shoulder portion (). The probe portion () has a length of 5.5 mm or more. In the friction stir welding tool (), a ceramic material whose main phase is silicon nitride or sialon is used as a base material.

A low-temperature joining method effectively suppresses reductions in the mechanical properties of a junction of various types of high-tensile steel or aluminum, and of a heat-affected zone; and produces a joint structure. A method for joining two metal materials by forming a joint interface in which the two metal materials face each other at a joint portion and plunge a rotation tool caused to rotate at a prescribed speed into the joint, the method for low-temperature joining of metal materials characterized in that the peripheral velocity of the outermost periphery of the rotation tool is set to 51 mm/s or less, whereby the recrystallization temperature inherent to the metal materials is reduced by introducing a large strain to the joint, and recrystallized grains are generated at the joint interface by setting the joining temperature to less than the recrystallization temperature inherent to the metal materials.

Method for low-temperature joining of metal materials, and joint structure

A dissimilar material solid phase bonding method is disclosed wherein one member and another member having different compositions are brought into contact with one another by way of an insert material to form an interface () to be bonded, at which the one member and the insert material are in contact with one another, and an interface () to be bonded, at which the other member and the insert material are in contact with one another; the temperature of the interface () to be bonded and the interface () to be bonded is raised by means of frictional heat and/or by electrical heating; a bonding pressure () is applied substantially perpendicular to the interface () to be bonded; a bonding pressure () is applied substantially perpendicular to the interface () to be bonded; and the bonding pressure () and the bonding pressure () are set to different values.

Dissimilar material solid phase bonding method, dissimilar material solid phase bonded structure, and dissimilar material solid phase bonding device

A friction stir welding tool member according to the present embodiment has a shoulder portion and a probe portion concentrically projecting from an upper surface of the shoulder portion. The shoulder portion includes a curved surface processed portion that is curved to have a curved shape on an outer peripheral edge of the shoulder portion. A space occupancy occupied by the two-dimensional space in which neither the shoulder portion nor the probe portion exists is in a range of 30% to 70%, the space occupancy being determined based on a projection drawing of a side surface region surrounded from a tip of the probe portion to the curved surface processed portion of the shoulder portion.

Friction stir welding tool member, and friction stir welding method using the same

To provide a solid phase welding method and a solid phase welding apparatus which are possible to accurately control the welding temperature, to lower the welding temperature and to achieve a solid phase welding of the metallic materials. The present invention provides a solid phase welding method for metallic materials comprising, a first step of forming an interface to be welded by abutting end portions of one material to be welded and the other material to be welded and applying a pressure in a direction substantially perpendicular to the interface to be welded, a second step of raising a temperature of the vicinity of the interface to be welded to a welding temperature by an external heating means, wherein the pressure is set to equal to or more than the yield strength of the one material to be welded and/or the other material to be welded at the welding temperature.

Metal material solid-phase bonding method and solid-phase bonding device

Provided are a long-life and inexpensive friction stir welding tool that is not dependent on the mode of friction stir welding or the type of material to be welded, and a friction stir welding method using the friction stir welding tool. The friction stir welding tool comprises a body portion having a shoulder portion, and a probe portion disposed on a bottom surface of the body portion, and is characterized in that the probe portion is spherical-crown shaped. Preferably, the shoulder portion is flat or convex, and preferably the hardness of the shoulder portion is greater than the hardness of the probe portion.

A linear friction welding method capable of accurately controlling a welding temperature and capable of lowering the welding temperature is provided. The present invention is a linear friction welding method comprising: a first step of forming a welded interface by bringing one member into contact with the other member; a second step of repeatedly sliding one member and the other member on the same locus and discharging flash from the welded interface in a state where pressure is applied substantially perpendicularly to the welded interface; and a third step of forming a welded surface by stopping the sliding and setting the pressure to be not less than the yield stress and not more than the tensile strength of one member and/or the other member at a desired welding temperature.

Linear friction welding method

Provided are a simple and effective friction welding method that can suppress increases in hardness of the welded part and reductions in hardness (strength) in the heat affected zone regardless of the composition of ferrous material, and a welded structure obtained with the same. The present invention relates to a friction welding method wherein surfaces to be welded of two metal members () to be welded are made to slide in contact with each other. The friction welding method is characterized in that at least one of the metal members () to be welded is a ferrous material, and the maximum temperature reached during welding is equal to or less than the Apoint or equal to or less than the Apoint of the ferrous material. The maximum temperature reached during welding is preferably equal to or less than the A1 point of the ferrous material.

Friction bonding method

The friction stir welding tool member according to the present invention is made of a ceramic member in which a shoulder portion and a probe portion are integrally formed, wherein a root portion of the probe portion and an end portion of the shoulder portion have a curved surface shape; and the friction stir welding tool member has a ratio (R1/D) of 0.02 or more and 0.20 or less when a curvature radius of the end portion of the shoulder portion is defined as R1 (mm) and an outer diameter of the shoulder portion is defined as D (mm). In addition, the ceramic member is preferably made of a silicon nitride sintered body having a Vickers hardness of 1400 HV1 or more. According to the above-described configuration, a friction stir welding tool member having excellent durability can be provided.

Friction stir welding tool member, friction stir welding apparatus using the same, and friction stir welding method

The present invention provides a friction welding method capable of reducing the welding temperature and a friction welding method capable of obtaining a welded portion free of defects regardless the type of material. A frictional welding method in which one member is brought into contact with the other member and slides while a load is applied substantially perpendicularly to the interface to be welded, the frictional welding method comprising: a first step in which frictional welding is carried out by setting a pressure calculated from the area and the load of the interface to be welded to be equal to or higher than the yield stress and the tensile strength of one member and/or the other member at a desired welding temperature; and a second step in which frictional welding is carried out by lowering the load, wherein the first step and the second step are continuously carried out.

The friction stir welding tool member according to the present invention is made of a silicon nitride sintered body, wherein the silicon nitride sintered body contains 15% by mass or less of additive components except silicon nitride in such a manner that the additive components include at least one element selected from lanthanoid elements and at least one element selected from Mg, Ti, Hf, and Mo. In addition, it is preferable that the additive components further include at least one element selected from Al, Si, and C. According to the above-described configuration, a friction stir welding tool member having an excellent durability can be provided.

Friction stir welding tool member made of silicon nitride sintered body, and friction stir welding apparatus using the same

A base material of a ferrous material is heated to an Apoint, which is a temperature to cause austenite appearance, or higher, and austenite appears in the base materialand(S). An amount of a strain assuming that an Mpoint, which is a temperature where the base material becomes martensite completely, is decreased to be less than room temperature is introduced into the base material (S). The all ferrous material becoming martensite on the occasion of cooling the ferrous material to room temperature is prevented. The base material is cooled to room temperature at a cooling rate where a line extrapolated a cooling curve of the base material intersects with a region where martensite is produced on the CCT diagram (S). Austenite remains in the manufactured ferrous material at room temperature.

Growing community of inventors

Suita, Japan

Yoshiaki Morisada