Hardening effect of multi-energyW2+-ion irradiation on tungsten–potassium alloy
Hardening effect of multi-energyW2+-ion irradiation on tungsten–potassium alloy
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DOI：
10.1088/1674-1056/ab9c09
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发表时间：
2020-06
影响因子：
1.7
通讯作者：
Yangyipeng Song;W. Qiu;Longqing Chen;Xiaoliang Yang;Hao Deng;Changsong Liu;Kun Zhang;Jun Tang
中科院分区：
文献类型：
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作者：
Yangyipeng Song;W. Qiu;Longqing Chen;Xiaoliang Yang;Hao Deng;Changsong Liu;Kun Zhang;Jun Tang
钨是未来最有希望在核聚变反应堆中用作偏滤器材料的面向等离子体材料（PFM）之一。在这项工作中，采用W 2+ 离子轰击模拟了商业纯钨（W）和轧制钨钾（W-K）的中子辐照损伤。在923 K下依次施加3× 10 15 W 2+-ions/cm 2 的7 MeV、4.5× 10 14 W 2+ 的3 MeV和3× 10 14 W 2+-ions/cm 2 的2 MeV，在样品表面下方产生100 nm-400 nm的均匀区域，最大损伤值为11.5 dpa。纳米压痕用于检查自离子辐照后硬度和弹性模量的变化。两种材料均发生辐射硬化。轧制W-K的辐照硬化受两个因素的影响：一是钾气泡对空位和间隙原子的吸收，二是钾气泡与位错之间的相互作用。在11.5dpa的条件下，缺陷吸收能力可以达到阈值。结果，位错最终主导了轧制 W-K 的硬化。通过透射电子显微镜 (TEM) 进一步观察 W-K 位错环的具体特征，以解释硬化效应。这项工作可能为 W-K 合金作为一种有前途的等离子体表面材料候选提供有价值的启示。
Tungsten is one of the most promising plasma-facing materials (PFMs) to be used in the nuclear fusion reactor as divertor material in the future. In this work, W 2+-ions bombardment is used to simulate the neutron irradiation damage to commercial pure tungsten (W) and rolled tungsten–potassium (W–K). The 7 MeV of 3× 10 15 W 2+-ions/cm 2, 3 MeV of 4.5× 10 14 W 2+, and 2 MeV of 3× 10 14 W 2+-ions/cm 2 are applied at 923 K in sequence to produce a uniform region of 100 nm–400 nm beneath the sample surface with the maximum damage value of 11.5 dpa. Nanoindentation is used to inspect the changes in hardness and elastic modulus after self-ion irradiation. Irradiation hardening occurred in both materials. The irradiation hardening of rolled W–K is affected by two factors: one is the absorption of vacancies and interstitial atoms by potassium bubbles, and the other is the interaction between potassium bubbles and dislocations. Under the condition of 11.5 dpa, the capability of defect absorption can reach a threshold. As a result, dislocations finally dominate the hardening of rolled W–K. Specific features of dislocation loops in W–K are further observed by transmission electron microscopy (TEM) to explain the hardening effect. This work might provide valuable enlightenment for W–K alloy as a promising plasma facing material candidate.