Production method for magnesium-containing metal material provided with coating

Abstract

Provided is a magnesium-containing metal material that includes coatings having excellent corrosion resistance on a surface. Specifically, provided is a magnesium-containing metal material with coating, which is characterized by including: a magnesium hydroxide-containing first coating on a surface of a magnesium-containing metal material composed of magnesium or a magnesium alloy; a hydroxyapatite and/or hydroxyapatite carbonate-containing third coating over the first coating; and a dibasic calcium phosphate-containing second coating between the first coating and the third coating.

1 . A production method for magnesium-containing metal material consisting of a magnesium or a magnesium alloy with coating comprising:
 a first step of forming a first coating on the surface of a magnesium-containing metal material to obtain a magnesium-containing metal material with the first coating;   the second step of forming a second coating including a dibasic calcium phosphate over the first coating by contacting chemical conversion agent including the phosphate ion and the calcium ion with the magnesium-containing metal material with the first coating;   and a third step of forming a third coating by contacting an aqueous alkaline solution with the second coating to convert some or all of dibasic calcium phosphate crystals on the surface of the second coating into hydroxyapatite and/or hydroxyapatite carbonate.   
     
     
         2 . The production method for magnesium-containing metal material consisting of a magnesium or magnesium alloy with coating according to  claim 1 , wherein the first step comprises a steam treatment method. 
     
     
         3 . The production method for magnesium-containing metal material consisting of a magnesium or magnesium alloy with coating according to  claim 1 , further comprising a surface conditioning step to contact surface conditioner including dibasic calcium phosphate particles with the magnesium-containing metal material with the first coating after the first step but prior to the second step. 
     
     
         4 . The production method for magnesium-containing metal material consisting of a magnesium or magnesium alloy with coating according to  claim 3 , wherein the dibasic calcium phosphate particles are particles of monetite and/or brushite. 
     
     
         5 . The production method for magnesium-containing metal material consisting of a magnesium or magnesium alloy with coating according to  claim 3 , wherein the dibasic calcium phosphate particles has a D 50  of 0.1 μm or larger, 0.8 μm or smaller, and a D 90  of 0.15 μm or larger, 1.5 μm or smaller.