Linear friction-joining method and linear friction-joining structure
Provided are an easy and efficient linear friction-joining method with which it is possible to form an excellent joined section between materials being joined that are of different sizes and shapes, and a linear friction-joining structure obtained through the aforementioned friction-joining method. The present invention discloses a linear friction-joining method characterized by having a first step for bringing an end surface of one member into contact with an end surface of another member to form a joining interface, a second step for repeatedly causing the one member and the other member to slide on the same trajectory in a state in which pressure is applied roughly perpendicularly to the joining interface and eliminating burrs from the joining interface, and a third step for stopping the sliding and forming a joined surface, the linear friction-joining method also being characterized in that the end surface of the one member and the end surface of the other member have different surface areas, and in that the protrusion length of the member having the lesser surface area is set equal to or greater than the upset distance.
1 . A linear friction-joining method which comprises:
a first step of forming an interface to be joined by bringing an end surface of one member into contact with an end surface of an other member while each of the one member and the other member is fixed to a linear friction-joining apparatus by a fixing jig;
a second step of repeatedly sliding the one member and the other member on the same trajectory to discharge burr from the interface to be joined while applying a pressure substantially perpendicular to the interface to be joined; and
a third step of stopping the sliding to form a joined surface;
wherein an entire area of an entirety of the end surface of the other member is smaller than an entire area of an entirety of the end surface of the one member,
a total length of the one member and the other member in a direction in which the pressure is applied immediately after the third step is shorter than a total length of the one member and the other member in the direction in which the pressure is applied after the first step and before the second step, and
the linear friction-joining method further comprises setting a protrusion length of the other member and an upset distance such that the protrusion length of the other member is equal to or larger than an upset distance, the protrusion length being a length of a material to be joined protruding to a side of the interface from the fixing jig at the first step, the upset distance being a difference between the total length of the one member and the other member in the direction in which the pressure is applied after the first step and before the second step and the total length of the one member and the other member in the direction in which the pressure is applied immediately after the third step.
2 . The linear friction-joining method according to claim 1 , wherein the amount of burr discharged in the direction substantially perpendicular to the sliding direction is larger than the amount of burr discharged in the direction substantially parallel to the sliding direction.
3 . The linear friction-joining method according to claim 1 , wherein, with respect to the other member, the length in the direction substantially perpendicular to the sliding direction is made shorter than the length in the direction substantially parallel to the sliding direction.
4 . The linear friction-joining method according to claim 1 , wherein a thermal conductivity of the one member and/or the other member is 10 W/mK or more.
5 . The linear friction-joining method according to claim 1 , wherein the one member and/or the other member is any one of ferrous metals, aluminum, aluminum alloys, magnesium, magnesium alloys, copper and copper alloys.
6 . The linear friction-joining method according to claim 1 , wherein the protrusion length is equal to or greater than the sum of the upset distance and the thickness of the burr.
7 . The linear friction joining method according to claim 1 , wherein the one member and the other member are made of different materials.
8 . The linear friction-joining method according to claim 7 , wherein the materials of the one member and the other member are selected so that the strength of the other member is lower than the strength of the one member at a desired joining temperature.
9 . The linear friction-joining method according to claim 1 , wherein the pressure is set to be equal to or higher than the yield stress and equal to or lower than the tensile strength of the one member and/or the other member at a desired joining temperature.
10 . The linear friction-joining method according to claim 1 , wherein the protrusion length is set to be equal to or greater than the upset distance and less than the sum of the upset distance and the thickness of the burr.