Preface to the special issue: novel applications of main refractory metals and their compounds

Tungsten is an important material widely used not only in traditional refractory applications,but also in new functional areas.Launched in early 2019,Tungsten journal is dedicated to the science and technology of tungsten and related met-als,including molybdenum,cobalt,vanadium,tantalum,nio-bium,rhenium,as well as their alloys and compounds.