Abstract: A microwave waveguide or resonator for conducting microwaves of high energy density at high temperature for sintering hard materials has a support of a highly heat-resistant material and a laminated body at least partially mounted on the support and having a surface coating consisting of nitrides, carbides, or carbonitrides of elements of the IVa to VIa groups of the periodic system and having a thickness between 0.10 &mgr;m and 100 &mgr;m.

Abstract: Disclosed are a composite body and the production and the use thereof. It consists of a substrate body with a single- or multilayer coating, containing either Ti, Zr, Hf, V, Nb carbides, nitrides, carbonitrides and/or Ta and/or Al2O3 or ZrO2. In order to improve the characteristics of wear from chip removal or another form of abrasion, the invention suggests that a layer of Zr, Hf, V, Nb, Ta or Cr carbonitride be precipitated either directly upon a layer of Al2O3— or ZrO2— or upon a thin intermediate layer of ZrC or ZrN up to 0,5 &mgr;m, or upon a TiN layer up to 0.1 &mgr;m, or indirectly upon a layer of Al2O3— or ZrO2—.