Views:5 Author:Site Editor Publish Time: 2017-08-15 Origin:Site
Molybdenum wire is made from molybdenum rods with series of processing such as hot-rolling, forging, drawing and made into a variety of specifications. Molybdenum wire often breaks in the drawing production process , resulting in molybdenum wire into the material rate. Therefore, in order to improve the true sense of the molybdenum wire finished product rate, to understand the molybdenum wire production process is particularly important.
Through the study molybdenum wire fracture for the following reasons:
1) Brittle fracture caused by center hole of molybdenum rod blanks.
Molybdenum rods are produced from molybdenum powder by powder metallurgy with porous. After the hot forming and rolling, if the compression is not uniform, the cross-sectional area of the force is changed after the subsequent drawing, resulting in a large fluctuation in the deformation direction, resulting in the molybdenum wire fracture.
2) impurity element enrichment can lead to brittle fracture
There’re two kinds of impurity enrichment in the metal molybdenum , one is enriched in the hole wall, the other is embedded in the metal molybdenum. High temperature strength and tensile strength of impurities are not as high as molybdenum metal so it’s easy to break at high temperatures.
3) Brittle fracture caused by inner cracks
Deformation of the material is not synchronized during hot forming procedure will cause molybdenum wire cracks. The formation of cracks in continuous drawing processing, when the tensile stress or stress concentration will further expand the crack, once the crack Expansion is too large, will eventually lead to molybdenum wire fracture phenomenon.