METHOD FOR EVALUATING VIBRATION RESISTANCE CHARACTERISTIC FOR FILAMENT WIRE AND TUNGSTEN WIRE FOR HIGH VIBRATION-RESISTANCE FILAMENT

摘要

PURPOSE:To evaluate the quality at the stage of wire material, to facilitate test working and to make it possible to perform quick working by performing the first heat treatment under the state wherein a bob having a specified weight is hooked at the tip of a test piece that is suspended vertically, performing the second heat treatment under the state wherein the test piece is horizontally held in a cantilever state, and measuring the deformed amount. CONSTITUTION:At first, a tungsten wire material for a filament having a diameter of 0.39mm is formed into a hair pin shape whose opening width W of a V pattern is 12mm and height L is 130mm, and a test piece 3 is prepared. Then a bob 6 having a specified weight is hooked at the tip of the test piece which is suspended vertically. Under this state, a current which is 60% of the fusing current for the wire material is conducted for 30 seconds. After the first heat treatment, the bob 6 is removed. Then, the test piece 3 is horizontally held in a cantilever state. Under this state, a current which is 90% of the fusing current of the wire material is conducted again for 300 seconds, and the second heat treatment is performed. The amounts of deformation from the horizontal position of the free end of the test piece before and after the second heat treatment measured. The amount of the deformation is compared with the wire material, and the vibration resistance characteristic of the wire material is evaluated.