Tungsten tube may be prepared by chemical vapor deposition (CVD). CVD technology is an important method for producing pure tungsten products. In the late 1980s, it has been reported that CVD technology was used to prepared high-density, high-purity tungsten products abroad. In recent years, a large number of researches on the process, microstructure, and properties of CVD tungsten coatings also have been carried out in China.
The tungsten tube produced by CVD technology may appear crack. And the cracked tungsten tube was investigated by ring machine cutting method and X ray stress analysis system. The results showed that crack initiating at two neighboring columnar crystal grain boundaries of the internal surface with the action of large residual tensile stress in the internal surface of the tungsten tube, and the propagation expended from columnar crystal grain boundaries to the outer surface of the tungsten tube. The existence of a large residual compressive stress on the outer surface of tungsten tube can arrest propagating cracks.
More details, please visit:
http://www.tungsten.com.cn/tungsten-tube.html
