The invention discloses micron-nano pore gradient oxide ceramic films with biological activity, which are prepared by the following methods: The surface structures are biomedical engineering materials; Inorganic precursor coating solutions or the organic precursor coating solutions are prepared with or without micron and nanopore additives; The surface structures of the substrate are treated in the following steps: (1) The surfaces of the substrate are coated by the inorganic precursor coating solutions or the organic precursor coating solutions with or without micron and nanopore additives; (2) The substrate with coatings are dried, sintered, naturally cooled, and cleaned. (3) The biomedical engineering materials with the micron-nanopore gradient oxide ceramic films, especially biomimetic micro-nanoporous gradient alumina film, yttrium partially stabilized zirconia film, and alumina doped yttrium partially stabilized zirconia films in this invention greatly improve biocompatibility and biological activity.

The invention discloses micron-nano pore gradient oxide ceramic films with biological activity, which are prepared by the following methods: The surface structures are biomedical engineering materials; Inorganic precursor coating solutions or the organic precursor coating solutions are prepared with or without micron and nanopore additives; The surface structures of the substrate are treated in the following steps: (1) The surfaces of the substrate are coated by the inorganic precursor coating solutions or the organic precursor coating solutions with or without micron and nanopore additives; (2) The substrate with coatings are dried, sintered, naturally cooled, and cleaned. (3) The biomedical engineering materials with the micron-nanopore gradient oxide ceramic films, especially biomimetic micro-nanoporous gradient alumina film, yttrium partially stabilized zirconia film, and alumina doped yttrium partially stabilized zirconia films in this invention greatly improve biocompatibility and biological activity.

A roller for a roller furnace with a roller base body and a coating on the surface, wherein the coating has a first layer, containing: 10.0-30.0 wt.-% Si, 10.0-30.0 wt.-% Al(OH).sub.3, 1.0-3.0 wt.-% B.sub.4C, 0.5-1.5 wt.-% Y.sub.2O.sub.3, 0.1-1.0 wt.-% Fe.sub.2O.sub.3 and the remainder Al.sub.2O.sub.3 and a second layer, containing 10.0-30.0 wt.-% Si, 10.0-30.0 wt.-% Al(OH).sub.3, 1.0-3.0 wt.-% B.sub.4C, 2.0-4.0 wt.-% Y.sub.2O.sub.3 and the remainder Al.sub.2O.sub.3.

A roller for a roller furnace with a roller base body and a coating on the surface, wherein the coating has a first layer, containing: 10.0-30.0 wt.-% Si, 10.0-30.0 wt.-% Al(OH).sub.3, 1.0-3.0 wt.-% B.sub.4C, 0.5-1.5 wt.-% Y.sub.2O.sub.3, 0.1-1.0 wt.-% Fe.sub.2O.sub.3 and the remainder Al.sub.2O.sub.3 and a second layer, containing 10.0-30.0 wt.-% Si, 10.0-30.0 wt.-% Al(OH).sub.3, 1.0-3.0 wt.-% B.sub.4C, 2.0-4.0 wt.-% Y.sub.2O.sub.3 and the remainder Al.sub.2O.sub.3.

A part includes a substrate having, adjacent to a surface of the substrate, at least a portion that is made of a material that contains silicon, and an environmental barrier formed on the surface of the substrate, the environmental barrier including a first layer including at least one first rare earth silicate and presenting grains with a mean size less than or equal to 1 m; and a second layer covering the first layer, the second layer including at least one rare earth silicate and presenting grains with a mean size greater than 1 m.

A part includes a substrate having, adjacent to a surface of the substrate, at least a portion that is made of a material that contains silicon, and an environmental barrier formed on the surface of the substrate, the environmental barrier including a first layer including at least one first rare earth silicate and presenting grains with a mean size less than or equal to 1 m; and a second layer covering the first layer, the second layer including at least one rare earth silicate and presenting grains with a mean size greater than 1 m.

A part includes a substrate, having, adjacent to a surface of the substrate, at least a portion that is made from a material that contains silicon, and an environmental barrier formed on the surface of the substrate, the environmental barrier including at least a first layer including a rare earth disilicate of formula RE.sup.a.sub.2Si.sub.2O.sub.7 present at a molar content lying in the range 70% to 99.9%, where RE.sup.a is a rare earth element; and at least one rare earth oxide of formula RE.sup.b.sub.2O.sub.3 present at a molar content lying in the range 0.1% to 30%, where RE.sup.b is a rare earth element different from RE.sup.a.

A part includes a substrate, having, adjacent to a surface of the substrate, at least a portion that is made from a material that contains silicon, and an environmental barrier formed on the surface of the substrate, the environmental barrier including at least a first layer including a rare earth disilicate of formula RE.sup.a.sub.2Si.sub.2O.sub.7 present at a molar content lying in the range 70% to 99.9%, where RE.sup.a is a rare earth element; and at least one rare earth oxide of formula RE.sup.b.sub.2O.sub.3 present at a molar content lying in the range 0.1% to 30%, where RE.sup.b is a rare earth element different from RE.sup.a.

A coated cutting tool includes a body and a hard and wear resistant PVD coating on the body, wherein the body is made from a cemented carbide, cermet, ceramics, polycrystalline diamond or polycrystalline cubic boron nitride based materials. The coating includes a first (Ti,Al)-based nitride sub-coating and a second (Ti,Al)-based nitride sub-coating. The first (Ti,Al)-based nitride sub-coating can be a single layer, and the second (Ti,Al)-based nitride sub-coating can be a laminated structure, wherein the first (Ti,Al)-based nitride sub-coating includes a (Ti.sub.1-xAl.sub.x)N.sub.z-layer where 0.1<x<0.4, 0.6<z<1.2, and wherein the second (Ti,Al)-based nitride sub-coating includes a (Ti.sub.1-x1-y1Al.sub.x1Cr.sub.y1)N.sub.z1 layer where 0.5<x1<0.75, 0.05<y1<0.2, 0.6<z1<1.2.

A coated cutting tool includes a body and a hard and wear resistant PVD coating on the body, wherein the body is made from a cemented carbide, cermet, ceramics, polycrystalline diamond or polycrystalline cubic boron nitride based materials. The coating includes a first (Ti,Al)-based nitride sub-coating and a second (Ti,Al)-based nitride sub-coating. The first (Ti,Al)-based nitride sub-coating can be a single layer, and the second (Ti,Al)-based nitride sub-coating can be a laminated structure, wherein the first (Ti,Al)-based nitride sub-coating includes a (Ti.sub.1-xAl.sub.x)N.sub.z-layer where 0.1<x<0.4, 0.6<z<1.2, and wherein the second (Ti,Al)-based nitride sub-coating includes a (Ti.sub.1-x1-y1Al.sub.x1Cr.sub.y1)N.sub.z1 layer where 0.5<x1<0.75, 0.05<y1<0.2, 0.6<z1<1.2.