Joining state detection film, joining state detection device, and joining state detection method
View Patent ↗An object is to provide a joining state detection film, a joining state detection device, and a joining state detection method, capable of detecting a joining state of a joining portion of two members from the outside. [Solution]A film containing a mechanoluminescent substance is formed on a surface, on a side opposite to a joining surface, of at least one member of two members that are joined at joining parts each having the joining surface, and physical stimulation is applied thereto.
1. A joining state detection method for detecting a joining state of two members that are joined at joining parts each having a joining surface, the method comprising the steps of:
forming the joining state detection film containing a mechanoluminescent substance on a first surface of a first of the two joining parts, the first surface being opposite to the joining surface of the first joining part; and
physically stimulating the joining part such that light is emitted from a luminescent part of the joining state detection film and light is not emitted from a non-luminescent part of the joining state detection film and an area of the non-luminescent part indicates an area of the joining surface where the two members are not joined.
2. The joining state detection method according to claim 1 , wherein the mechanoluminescent substance contained in the joining state detection film is a substance represented by SrAl 2 O 4 that is doped with Eu 2+ , a substance represented by SrAl 2 O 4 that is doped with at least one of Eu 2+ , Ho 3+ , Dy 2+ , M 1 , M 2 , and M 3 (M 1 , M 2 , and M 3 are monovalent to trivalent different metal ions), or a substance represented by CaYAl 3 O 7 that is doped with Eu 2+ .
3. The joining state detection method according to claim 1 , wherein the two members are joined using an adhesive, a rivet, a bolt and a nut, a screw, a clinching fastener, and swaging.
4. The joining state detection method according to claim 1 , wherein the two members are joined by static electricity, anodic bonding, or welding.
5. The joining state detection method according to claim 1 , wherein a joining strength between the two members is detected on a basis of an area ratio of the luminescent part to the joining surface.
6. The joining state detection method according to claim 1 , wherein the step of forming a joining state detection film further forms a joining state visualization film containing a mechanoluminescent substance on at least one of a side surface and an end surface of the joining part.