Disruption tests on repaired tungsten by CVD coating

The chemical vapor deposition (CVD) coating is considered as one of the possible methods for in situ repairing of the tungsten armor. In the present work, CVD coatings on eroded tungsten specimens were prepared to investigate the applicability of this method to repair the eroded tungsten surface. To simulate the damaged surface relevant to the disruption erosion, specimens were irradiated by an electron beam at a heat flux of 1250 MW/m2 before the CVD repairing procedure. From metallographic results, no pores or cracks were observed at the interface between the CVD layer and the eroded layer seemed to be successfully repaired by the CVD coating. However, the CVD layer was delaminated by thermal shock tests which simulate disruption heat loads. It was found that complete removal of the resolidified area before CVD coating is effective to repair the eroded surface.