Provided is a method for manufacturing a liquid-cooled jacket, to reduce the size of a recessed groove on a surface of a metal member and also to reduce roughness of a jointed surface. The method includes: a placing step of placing a sealing body on a jacket body, a first main joining step of performing friction stirring by moving a main joining rotary tool around to a first overlapped portion, and a second main joining step of performing friction stirring to a second overlapped portion. The main joining rotary tool has a base-end-side pin and a tip-end-side pin. A taper angle of the base-end-side pin is greater than a taper angle of the tip-end-side pin and a stairs-like pin step portion is formed on an outer circumferential surface of the base-end-side pin.

A method of friction stir processing (FSP) includes contacting a first workpiece with a FSP tool, where the first workpiece is a low-melting temperature metal or alloy and the FSP tool is a single-body FSP tool having a diamond working surface. The method also includes rotating the FSP tool in contact with the first workpiece at an interface and generating thermal energy at the interface to heat the first workpiece. The method further includes conducting thermal energy away from the interface with the FSP tool, and friction stirring the first workpiece at a temperature of the FSP tool below 800° C.

A friction stir processing (FSP) tool includes a working material. The working material has a matrix phase and a particulate phase. The matrix phase includes tungsten and an alloy material. The particulate phase is located within the matrix phase, and the particulate phase has an indentation hardness less than 45 GPa.

Disclosed is a friction stir welding tool with an adjustable probe length and shoulder groove depth, wherein a support shaft, made of a material having low thermal conductivity so as to inhibit thermal conduction between a probe and a shank, is coupled to the center of an upper locking member together with the shank, the probe and inner and outer shoulders are coupled inside a lower part of the upper locking member, and a lower locking member is fastened and fixed to the lower part of the upper locking member, and a washer and a locking nut are fastened to an upper part of the lower locking member, whereby the locking nut pushes the lower locking member via the washer.

A method for manufacturing a liquid-cooling jacket (1) where heat transfer fluid flows in a hollow part (14) defined by a jacket body (2) and a sealing body (3) includes: an overlapping process in which the sealing body (3) is placed on an end surface (11a) of a peripheral wall part (11) in such a way that the end surface (11a) and a back surface of the sealing body (3) are overlapped each other to form a first overlapped part (H1); and a primary joining process in which primary joining is performed by friction stirring in such a way that a rotary tool (F1) is moved once around a recessed part (13) along the first overlapped part (H1). In the primary joining process, the first overlapped part (H1) is joined in a state where the tip side pin is in contact with only the sealing body (3) or with the jacket body (2) and the sealing body (3) while the base side pin is in contact with the sealing body (3).

The present invention is characterized by including a heat medium pipe insertion process to insert a heat medium pipe into a concave groove; a lid plate insertion process to insert a lid plate into a lid groove; and a joining process to perform friction stirring while a primary joining rotary tool provided with a base side pin and a tip side pin is moved along a butted portion of a side wall of the lid groove and a side face of the lid plate, wherein in the joining process, friction stirring is performed while the tip side pin of the primary rotary tool which is rotating is inserted into the butted portion and an outer circumferential face of the base side pin is in contact with the base member and the lid plate, and plastically fluidized material fluidized by frictional heat is flowed into a void portion formed adjacent to the heat medium pipe.

The present invention includes: a preparation process configured to provide a first metal member including an end portion with a vertical face, and a second metal member including an end portion with an inclined face, a higher melting point and a smaller plate thickness than the first metal member; a butting process configured to butt the end portions of the first metal member and the second metal member against each other and form a butted portion with a V-shaped gap; and a joining process configured to join the first metal member and the second metal member together by inserting the rotating rotary tool from only a front face of the first metal member and relatively moving the rotary tool along the butted portion while only the stirring pin is in contact with at least the first metal member.

The disclosed friction bit joining systems may include a ball screw having an internal bore, a chuck and spindle configured to be rotated by a chuck spindle motor, a friction bit joining bit held by the chuck, a support frame, and a chuck driver motor positioned and configure to rotate the ball screw to axially move the chuck and the friction bit joining bit relative to the support frame. At least a portion of the spindle may be positioned within the internal bore of the ball screw. Various other related systems and methods are also disclosed.

The disclosure provides a friction stir welding tool which can inhibit chipping even if an adhesion matter having high hardness adheres to a tip thereof during friction stir welding of an iron-base alloy and an aluminum alloy. In the tool for friction stir welding made of high-speed tool steel that includes a minor diameter portion and a major diameter portion formed adjacently to the minor diameter portion, hardness of the tool decreases from the minor diameter portion toward the major diameter portion. The hardness of the minor diameter portion may be 65 HRC or more by Rockwell hardness C-scale, and the hardness of the major diameter portion may be 60 HRC or less by Rockwell hardness C-scale.

A hard disk drive includes a base deck with a floor portion and a side wall portion. The floor portion extends between an upper surface and a bottom surface, and the side wall portion extends from the floor portion. A top cover is coupled to the base deck and includes a ceiling portion and a wall portion. The hard disk drive includes a weld that directly couples the wall portion of the top cover to the floor portion of the base deck.