A decorative article (100) having an observed colour effect that is changeable depending on observer (200) viewing angle, the article comprising: a decorative element (110) comprising a front side (114) facing a forward direction and a back side (112) opposite the front side facing a rearward direction, wherein the back side comprises a back surface (113) having a first region (122) and a second region (124) surrounding the first region; a first coating (132) arranged on the first region of the back surface, the first coating causing a first colour effect (102); and a second coating (134) arranged on the second region of the back surface, the second coating causing a second colour effect (104) that differs from the first colour effect.

A decorative article (100) having an observed colour effect that is changeable depending on observer (200) viewing angle, the article comprising: a decorative element (110) comprising a front side (114) facing a forward direction and a back side (112) opposite the front side facing a rearward direction, wherein the back side comprises a back surface (113) having a first region (122) and a second region (124) surrounding the first region; a first coating (132) arranged on the first region of the back surface, the first coating causing a first colour effect (102); and a second coating (134) arranged on the second region of the back surface, the second coating causing a second colour effect (104) that differs from the first colour effect.

An article may include a substrate, such as a silicon-containing ceramic matrix composite, an environmental barrier coating (EBC) layer on the substrate, and a CMAS-resistant EBC layer on the EBC layer. The EBC layer may include at least one rare-earth disilicate (REDS). The CMAS-resistant EBC layer may include at least one rare-earth monosilicate (REMS) configured to react with CMAS to form crystalline reaction products. The CMAS-resistant EBC layer may include a plurality of vertical cracks extending from a surface of the CMAS-resistant EBC layer at least partially into the CMAS-resistant EBC layer. Additionally, or alternatively, the EBC layer may include a plurality of vertical cracks extending from a surface of the EBC layer into at least a portion of the EBC layer.

An article may include a substrate, such as a silicon-containing ceramic matrix composite, an environmental barrier coating (EBC) layer on the substrate, and a CMAS-resistant EBC layer on the EBC layer. The EBC layer may include at least one rare-earth disilicate (REDS). The CMAS-resistant EBC layer may include at least one rare-earth monosilicate (REMS) configured to react with CMAS to form crystalline reaction products. The CMAS-resistant EBC layer may include a plurality of vertical cracks extending from a surface of the CMAS-resistant EBC layer at least partially into the CMAS-resistant EBC layer. Additionally, or alternatively, the EBC layer may include a plurality of vertical cracks extending from a surface of the EBC layer into at least a portion of the EBC layer.

An automated preparation method of a SiC.sub.f/SiC composite flame tube, comprising the following steps: preparing an interface layer for a SiC fiber by a chemical vapor infiltration process, and obtaining the SiC fiber with a continuous interface layer; laying a unidirectional tape on the SiC fiber with the continuous interface layer and winding the SiC fiber with the continuous interface layer to form and obtaining a preform of a net size molding according to a fiber volume and a fiber orientation obtained in a simulation calculation; and adopting a reactive melt infiltration process and the chemical vapor infiltration process successively for a densification and obtaining a high-density SiC.sub.f/SiC composite flame tube in a full intelligent way. The SiC.sub.f/SiC composite flame tube prepared by the present disclosure not only has a high temperature resistance, but also has a low thermal expansion coefficient, high thermal conductivity and high thermal shock resistance.

An automated preparation method of a SiC.sub.f/SiC composite flame tube, comprising the following steps: preparing an interface layer for a SiC fiber by a chemical vapor infiltration process, and obtaining the SiC fiber with a continuous interface layer; laying a unidirectional tape on the SiC fiber with the continuous interface layer and winding the SiC fiber with the continuous interface layer to form and obtaining a preform of a net size molding according to a fiber volume and a fiber orientation obtained in a simulation calculation; and adopting a reactive melt infiltration process and the chemical vapor infiltration process successively for a densification and obtaining a high-density SiC.sub.f/SiC composite flame tube in a full intelligent way. The SiC.sub.f/SiC composite flame tube prepared by the present disclosure not only has a high temperature resistance, but also has a low thermal expansion coefficient, high thermal conductivity and high thermal shock resistance.

An environmental barrier coating, comprising a substrate containing silicon; an environmental barrier layer applied to the substrate; the environmental barrier layer comprising an oxide matrix; an oxidant getter phase interspersed throughout the oxide matrix; and a self-healing phase interspersed throughout the oxide matrix.

An environmental barrier coating, comprising a substrate containing silicon; an environmental barrier layer applied to the substrate; the environmental barrier layer comprising an oxide matrix; an oxidant getter phase interspersed throughout the oxide matrix; and a self-healing phase interspersed throughout the oxide matrix.

Among two main surfaces of a heat dissipation member, one main surface is curved to be convex in an outward direction and the other convex in an inward direction. When a straight line passing through both endpoints P.sub.1 and P.sub.2 of the curve is l.sub.1, a point at which a distance to l.sub.1 on the curve is maximum is P.sub.max, an intersection point between l.sub.1 and a perpendicular drawn from P.sub.max to l.sub.1 is P.sub.3, a middle point of a line segment P.sub.1P.sub.3 is P.sub.4, an intersection point between the curve and a straight line that passes through P.sub.4 and is perpendicular to l.sub.1 is P.sub.mid, a length of the line segment P.sub.1P.sub.3 is L, a length of a line segment P.sub.3P.sub.max is H, and a length of a line segment P.sub.4P.sub.max is h, (2 h/L)/(H/L) is 1.1 or more.

Among two main surfaces of a heat dissipation member, one main surface is curved to be convex in an outward direction and the other convex in an inward direction. When a straight line passing through both endpoints P.sub.1 and P.sub.2 of the curve is l.sub.1, a point at which a distance to l.sub.1 on the curve is maximum is P.sub.max, an intersection point between l.sub.1 and a perpendicular drawn from P.sub.max to l.sub.1 is P.sub.3, a middle point of a line segment P.sub.1P.sub.3 is P.sub.4, an intersection point between the curve and a straight line that passes through P.sub.4 and is perpendicular to l.sub.1 is P.sub.mid, a length of the line segment P.sub.1P.sub.3 is L, a length of a line segment P.sub.3P.sub.max is H, and a length of a line segment P.sub.4P.sub.max is h, (2 h/L)/(H/L) is 1.1 or more.