Effect of 5 MeV Au3+ ions irradiation damage on surface blistering and deuterium retention behaviors in W and W-ZrC alloy

Abstract

The effects of 5 MeV Au3+ ions irradiation damage on surface blistering and deuterium (D) retention behaviors in tungsten (W) and W-0.5 wt% ZrC alloy (WZC) have been studied after exposure to a low energy (38 eV D-1) D plasma under the fluence of ∼1 × 1025 D m−2 at about 400 K. It is found that Au3+ ions irradiation significantly reduces the surface density of blisters for both W and WZC. However, the size of blisters becomes larger due to Au3+ ions irradiation. With increasing dpa, the surface density and average size of blisters on the surface of the WZC noticeably decrease. In the case of the W, the average size of blisters also decreases with dpa, but the surface density of blisters changes less. Most of the D (>60%) are trapped at the depth less than ∼3.5 µm and the D concentration increases with dpa for both WZC and W. Compared to W, the D concentration in the sub-surface region of WZC is higher at the same damage level. For both W and WZC, a new high-temperature desorption peak appears at ∼800 K, which is ascribed to the D trapping at vacancy-type defects induced by Au3+ ions irradiation. The D retention in both samples increases with dpa and saturates at a damage level between ∼0.4–1.7 dpa. The growth rate of D retention caused by ion irradiation damage in WZC is less than that in W, while the D retention in WZC is slightly higher than that in W.

Keywords

• W
• W-ZrC alloy
• Heavy ions irradiation
• D plasma
• Surface blistering
• D retention