There remain some drawbacks of mechanical properties of W materials as a plasma facing material (PFM) for fusion reactor divertors, which are low temperature brittleness, high ductile-to-brittle transition temperature (DBTT), and recrystallization-induced embrittlement. To solve these issues, development of W materials with improved thermo-mechanical properties, neutron irradiation tolerance, and possibility of mass-production with microstructural uniformity has been advanced for the last decade under the collaboration R&D by universities in Japan. In this paper, the effects of grain refining, K-doping, dispersion strengthening by La₂O₃ particles, and alloying by Re are discussed from the viewpoints of both short- and long-term material properties and phenomena, including effects of neutron irradiation and high heat loads, which should be considered under the actual fusion reactor environments. Through this R&D, K-doping and Re-addition showed several positive effects. Among the materials developed in this R&D, K-doped W-3%Re hot-rolled plate could be a better solution for PFM, which demonstrated superior properties from several perspectives. However, materials alloyed by Re have an intrinsic concern of higher irradiation hardening caused by neutron irradiation up to higher doses. Therefore, it is pointed out that investigations of thermo-mechanical properties under higher dose neutron irradiation are significantly required to realize long-term structural reliability and lifetime of fusion reactors.

W材料作为聚变反应堆偏滤器的面向等离子体材料（PFM）的机械性能仍然存在一些缺点，这些缺点是低温脆性，高延性至脆性转变温度（DBTT）和重结晶引起的脆化。为了解决这些问题，在日本大学的合作研发下，近十年来已开发出具有改进的热机械性能，中子辐照耐受性和具有微观结构均匀性的量产可能性的W材料。本文研究了La ₂ O ₃对晶粒细化，K掺杂，弥散强化的影响。从短期和长期的材料特性和现象（包括中子辐照和高热负荷的影响）的角度出发，讨论了粒子和Re的合金化，应在实际的聚变反应堆环境中加以考虑。通过这项研发，掺钾和再添加显示出一些积极的效果。在此研发中开发的材料中，掺K的W-3％Re热轧板可能是PFM的更好解决方案，从多个角度证明了其优越的性能。但是，由Re合金化的材料具有内在的担忧，即中子辐照直至更高剂量都会导致更高的辐照硬化。因此，