Disclosed are a method for forming a thermal barrier layer for a metallic component, which method involves forming a ceramic coat in which at least in part aluminum oxide and titanium oxide are disposed, the aluminum oxide and the titanium oxide being introduced by infiltration of aluminum-containing and titanium-containing particles or substances or by physical vapor deposition.

[Problem] To produce a DLC film excellent in hardness and adhesiveness while preventing a film-forming rate from slowing even when the gas pressure in a chamber is a low pressure without requiring a large-scale facility such as a thermostatic device. [solution] There is provided a DLC film film-forming method being a film-forming method to film-form a DLC film on a substrate by a plasma CVD method, the method including: setting a voltage to be applied to a substrate using a DC pulse power supply to a bias voltage; using an acetylene gas or a methane gas as a film-forming gas to be supplied into a chamber; setting the total pressure of the gas in the chamber to not less than 0.5 Pa and not more than 3 Pa when the methane gas is used; setting the total pressure of the gas in the chamber to not less than 0.3 Pa and not more than 3 Pa when the acetylene gas is used; and setting the bias voltage to not less than 0.9 kV and not more than 2.2 kV.

A gas turbine engine component includes a metal substrate and a coating system disposed on the metal substrate. The coating system includes at least one layer of aluminum-chromium oxide.

A sealing process includes applying a first reactant to a substrate having a porous structure, the first reactant comprising a chromium (III) precursor and a transition metal precursor and applying a second reactant to the first reactant, the second reactant comprising a rare earth element precursor and an alkaline earth element precursor to form reservoirs of trivalent chromium in pore space of the porous structure, and a physical barrier over the substrate and the reservoirs.

In an embodiment, a coated tool is disclosed. The coated tool includes a base material, a first layer on the base material, and a second layer coated on the first layer. The first layer contains diamond crystals therein and has a first mean crystal size. The second layer contains diamond crystals therein and has a second mean crystal size that is smaller than the first mean crystal size. The first and the second layers contain hydrogen, and have a first hydrogen content and a second hydrogen content respectively. The second hydrogen content is larger than the first hydrogen content.

A coated cutting tool comprising a substrate and a coating layer formed on a surface of the substrate, the coated cutting tool having a rake surface and a flank, in which the coating layer includes an -type aluminum oxide layer, wherein: the -type aluminum oxide layer has, on an opposite side to the substrate, a first interface, being the rake surface or a surface substantially parallel to the rake surface, a second interface, being the flank or a surface substantially parallel to the flank, and an intersecting edge between the first interface and the second interface; and a residual stress value (unit: GPa) measured near each of the first and second interfaces increases continuously or stepwise as a measurement position for the residual stress value becomes distant from the intersecting edge with distances of 10 m, 50 m, 100 m, 150 m and 200 m.

(In the above formulae, 11 denotes a residual stress value (MPa) in a direction parallel to the intersecting edge, 22 denotes a residual stress value (MPa) in a direction orthogonal to the intersecting edge, and each of the residual stress values is a value measured by a 2D method.)

A coating system disposed on a surface of a substrate is provided. The coating system may include a bond coating layer on the surface of the substrate, a dense TBC layer on the bond coating layer, and a columnar TBC layer on the dense TBC layer, with the columnar TBC layer defines a plurality of elongated surface-connected voids. The dense TBC layer generally includes a ceramic material and has a porosity of about 15% or less. A method is also provided for forming a coating system on a surface of a substrate.

The disclosure relates generally to recession resistant gas turbine engine articles that comprise a silicon containing substrate, and related coatings and methods. The present disclosure is directed, inter alia, to an engine article comprising a silicon substrate which is coated with a chemically stable porous oxide layer. The present disclosure also relates to articles comprising a substrate and a bond coat on top comprising a two phase layer of interconnected silicon and interconnected oxide, followed by a layer of silicon. The present disclosure further relates to a recession resistant article comprising an oxide in a silicon containing substrate, such that components of the silicon containing substrate is interconnected with oxides dispersed in the substrate and form the bulk of the recession resistant silicon containing article.

An article includes a substrate and a coating provided on a surface of the substrate. The coating includes at least one metal silicide layer consisting essentially of MoSi.sub.2 or WSi.sub.2 or (Mo, W)Si.sub.2 or a platinum group metal silicide and at least one layer consisting essentially of Si.sub.3N.sub.4.

A coated cutting tool comprising a substrate and a coating layer formed on a surface of the substrate, the coating layer including an alternating laminate structure in which two or more compound layers of each of two or three or more kinds, each kind having a different composition, are laminated in an alternating manner, wherein: the alternating laminate structure is constituted by: a compound layer containing a compound having a composition represented by formula (1) below:

(Ti.sub.xM.sub.ySi.sub.z)N(1)

[wherein M denotes an element of at least one kind selected from the group consisting of Zr, Hf, V, Nb, Ta, Cr, Mo, W and Al, x denotes an atomic ratio of Ti based on a total of Ti, an element denoted by M and Si, y denotes an atomic ratio of the element denoted by M based on a total of Ti, the element denoted by M and Si, z denotes an atomic ratio of Si based on a total of Ti, the element denoted by M and Si, x satisfies 0.20x0.50, y satisfies 0.20y0.50, z satisfies 0.03z0.30, and x, y and z satisfy x+y+z=1]; and a compound layer containing a compound having a composition represented by formula (2) below:

(Ti.sub.aM.sub.bSi.sub.c)N(2)

[wherein M denotes an element of at least one kind selected from the group consisting of Zr, Hf, V, Nb, Ta, Cr, Mo, W and Al, a denotes an atomic ratio of Ti based on a total of Ti, an element denoted by M and Si, b denotes an atomic ratio of the element denoted by M based on a total of Ti, the element denoted by M and Si, c denotes an atomic ratio of Si based on a total of Ti, the element denoted by M and Si, a satisfies 0.20a0.49, b satisfies 0.21b0.50, c satisfies 0.04c0.30, and a, b and c satisfy a+b+c=1]; an absolute value of a difference between an amount of a specific metal element contained in a compound layer which constitutes the alternating laminate structure based on an amount of all the metal elements contained therein and an amount of the specific metal element contained in another compound layer which is adjacent to the compound layer and which constitutes the alternating laminate structure based on an amount of all the metal elements contained therein, is more than 0 atom % and less than 5 atom %; and an average thickness of each of the compound layers is from 1 nm or more to 50 nm or less, and an average thickness of the alternating laminate structure is from 1.0 m or more to 15.0 m or less.