Surface coated member and method for manufacturing same

Abstract

A surface coated member having improved stability and a longer service life is provided. The surface coated member includes a base member and a hard coating formed on a surface thereof. The hard coating is constituted of one or more layers. At least one layer among the layers is a layer including hard particles. The hard particles include a multilayer structure having a first unit layer and a second unit layer being layered alternately. The first unit layer includes a first compound. The second unit layer includes a second compound. The first compound and the second compound are respectively made of one or more kind of element selected from the group consisting of a group 4 element, a group 5 element, a group 6 element of a periodic table, and Al, and one or more kind of element selected from the group consisting of B, C, N, and O.

1 . A surface coated member comprising a base member and a hard coating formed on a surface thereof,
 said hard coating being constituted of one or more layers,   at least one layer among said layers being a layer including hard particles,   said hard particles including a multilayer structure having first unit layers and second unit layers being layered alternately,   said first unit layer including a first compound, said first compound being made of one or more kind of element selected from the group consisting of a periodic table group 4 element, a periodic table group 5 element, a periodic table group 6 element, and Al, and one or more kind of element selected from the group consisting of B, C, N, and O,   said second unit layer including a second compound, said second compound being made of one or more kind of element selected from the group consisting of a periodic table group 4 element, a periodic table group 5 element, a periodic table group 6 element, and Al, and one or more kind of element selected from the group consisting of B, C, N, and O.   
     
     
         2 . The surface coated member according to  claim 1 , wherein
 said surface coated member includes an intermediate layer between said first unit layer and said second unit layer, and   a composition of said intermediate layer is changed continuously in its thickness direction from a composition of said first compound to a composition of said second compound.   
     
     
         3 . The surface coated member according to  claim 1 , wherein
 said layer including said hard particles includes a grain boundary layer in a grain boundary of said hard particles, said grain boundary including said first compound or said second compound.   
     
     
         4 . A method for manufacturing a surface coated member including a base member and a hard coating, said hard coating being formed on a surface of said base member and constituted of one or more layers, the method comprising:
 a CVD step of forming at least one layer among said layers by a CVD method,   said CVD step including:   an ejection step of ejecting a mixture gas, containing two or more kinds of elements selected from the group consisting of a periodic table group 4 element, a periodic table group 5 element, a periodic table group 6 element, and Al, and one or more kind of element selected from the group consisting of B, C, N, and O, to a surface of said base member; and   a cooling step of cooling said base member after said ejection step.   
     
     
         5 . The method for manufacturing a surface coated member according to  claim 4 , wherein, said base member is cooled at a rate greater than or equal to 7° C./min in said cooling step.