[Mechanical properties and phase transformation of super-elastic Ni-Ti alloy wires. Part 2: Changes of properties through heat treatment].
Three types of super-elastic Ni-Ti alloy orthodontic wires, SENTALLOY-BLUE (SB), YELLOW (SY) and RED (SR), on the change of properties were studied especially the reversible change of the load level, using three point bending test and DSC. The heat treatment at 440 degrees C caused the largest reduction in mechanical properties of SB and SY, and the 400 degrees C treatment did that of SR. The load level of SR was less changeable than those of SB and SY by the difference of heat treatment temperature. Mechanical properties of SY were almost reversible by the alternate heat treatment at 440 degrees C and 510 degrees C. Then the 440 degrees C-heat treatment increased the transformation temperature, and the 510 degrees C-heat treatment decreased them. The variation of the mechanical properties completely corresponded to the change in transformation temperature. The variation appears to result from some internal structure changes. Changes in mechanical properties are observed by heat treatment at 360, 400 and 480 degrees C, but the reversibilities were not so clear. The change of the properties of super-elastic wires are influenced by the kind of wire and the heat treatment condition. The reversible change in the mechanical properties seems to have many advantages over super-elastic Ni-Ti alloy orthodontic wires.
Hamanaka
H
H
Yoneyama
T
T
Doi
H
H
Okamoto
Y
Y
Mogi
M
M
Miura
F
F
D003722:Dental Alloys; D003799:Dental Stress Analysis; D009532:Nickel; D009967:Orthodontic Appliances; D009969:Orthodontic Wires; D013696:Temperature; D014025:Titanium
D003722:Dental Alloys; C040654:titanium nickelide; D009532:Nickel; D014025:Titanium