| 摘要 |
PURPOSE:To reduce the friction between molten metal and an ingot by forming the 1st covering layer consisting of >=1 kind of Ni and Co on the inside surface of a mold made of Cu or a Cu alloy having rough surfaces, and forming the 2nd covering layer consisting of specific contents of >=1 kind of P, B and >=1 kind of Ni, Co. CONSTITUTION:A rough surface of about 20-200 S (in accordance with JIS B 0601), more preferably about 50-150 S is formed on the inside surface of a mold made of Cu or a Cu alloy. A plating layer consisting of >=1 kind of Ni and Co is formed on the inside surface of the mold, and further, an alloy plating layer consisting, by weight %, of >=1 kind of 3-20 P, and 2-15 B and the balance >=1 kind of Ni and Co is formed thereon. The effect is higher if the 3rd coating layer is formed thereon by carrying out Cr plating or forming an oxidized film by oxidizing said alloy plating layer. |
