COATING STRUCTURE, IMPELLER, COMPRESSOR, METAL PART MANUFACTURING METHOD, IMPELLER MANUFACTURING METHOD, AND COMPRESSOR MANUFACTURING METHOD
Said coating structure is provided with: a chemical conversion layer ( 11 ), which is formed by chemical conversion coating so as to cover the surface of an impeller body ( 10 ) obtained from a magnesium alloy that contains magnesium as the main component and which has a film thickness within a previously determined range; and a plating layer ( 12 ) formed so as to cover the chemical conversion layer ( 11 ).
1 - 8 . (canceled)
9 . A coating structure comprising:
a chemical conversion layer that contains magnesium as a main component and is made of a phosphate-coated film and is formed in a manner of covering a surface of a base material which is made of a magnesium alloy containing at least one kind of element selected from a group consisting of gadolinium, terbium, thulium, and lutetium; and
a plating layer that is made of a nickel-based alloy and is formed in a manner of covering the chemical conversion layer.
10 . The coating structure according to claim 9 ,
wherein the plating layer is formed of a nickel-phosphorous alloy.
11 . The coating structure according to claim 9 ,
wherein the base material contains a atom percent of zinc, contains b atom percent of at least one kind of element, in total, selected from a group consisting of gadolinium, terbium, thulium, and lutetium, has a remaining portion made of magnesium, and has the factors a and b satisfying the following expressions (1) to (3), and
wherein the base material has at least one kind of precipitate selected from a precipitate group consisting of a compound of magnesium and a rare earth element, a compound of magnesium and zinc, a compound of zinc and a rare earth element, and a compound of magnesium, zinc, and a rare earth element.
0.2≤ a≤ 5.0 (1)
0.5≤ b≤ 5.0 (2)
0.5 a− 0.5≤ b (3)
12 . An impeller comprising:
the coating structure according to claim 9 .
13 . A compressor comprising:
the impeller according to claim 12 .
14 . A metal part manufacturing method comprising:
a step of forming a chemical conversion layer by performing chemical conversion treatment in a manner of covering a surface of a base material which is made of a magnesium alloy containing magnesium as a main component; and
a step of forming a plating layer which is made of a nickel-based alloy in a manner of covering the chemical conversion layer.
15 . An impeller manufacturing method comprising:
the metal part manufacturing method according to claim 14 .
16 . A compressor manufacturing method comprising:
the impeller manufacturing method according to claim 15 .
17 . The coating structure according to claim 10 ,
wherein the base material contains a atom percent of zinc, contains b atom percent of at least one kind of element, in total, selected from a group consisting of gadolinium, terbium, thulium, and lutetium, has a remaining portion made of magnesium, and has the factors a and b satisfying the following expressions (1) to (3), and
wherein the base material has at least one kind of precipitate selected from a precipitate group consisting of a compound of magnesium and a rare earth element, a compound of magnesium and zinc, a compound of zinc and a rare earth element, and a compound of magnesium, zinc, and a rare earth element.
0.2≤ a≤ 5.0 (1)
0.5≤ b≤ 5.0 (2)
0.5 a− 0.5≤ b (3)
18 . An impeller comprising:
the coating structure according to claim 10 .
19 . An impeller comprising:
the coating structure according to claim 11 .