초록 ▼

The invention provides a pretreatment process for electroplating aluminum parts or strip, in which the zincating solution is modified to improve the adhesion of the subsequent electroplate to the substrate. The aluminum part or strip, such as an aluminum coin blank or strip for coin blanks, is pretr

The invention provides a pretreatment process for electroplating aluminum parts or strip, in which the zincating solution is modified to improve the adhesion of the subsequent electroplate to the substrate. The aluminum part or strip, such as an aluminum coin blank or strip for coin blanks, is pretreated with an improved zincate solution which provides hydroxide ions in an amount in the range of 75-175 gpl, zinc ions in an amount in the range of 15-40 gpl, nickel ions in an amount in the range of 2-10 gpl and copper ions in an amount in the range of 1.5-5 gpl. The pretreatment process preferably includes a copper strike applied from a copper cyanide strike bath at a pH in the range of 8.5-11.0, using a current density in the range of 0.1-10 A/dm2. The pretreatment and electroplating steps are preferably conducted by barrel plating, in accordance with another aspect of the invention.

대표청구항 ▼

The invention provides a pretreatment process for electroplating aluminum parts or strip, in which the zincating solution is modified to improve the adhesion of the subsequent electroplate to the substrate. The aluminum part or strip, such as an aluminum coin blank or strip for coin blanks, is pretr

The invention provides a pretreatment process for electroplating aluminum parts or strip, in which the zincating solution is modified to improve the adhesion of the subsequent electroplate to the substrate. The aluminum part or strip, such as an aluminum coin blank or strip for coin blanks, is pretreated with an improved zincate solution which provides hydroxide ions in an amount in the range of 75-175 gpl, zinc ions in an amount in the range of 15-40 gpl, nickel ions in an amount in the range of 2-10 gpl and copper ions in an amount in the range of 1.5-5 gpl. The pretreatment process preferably includes a copper strike applied from a copper cyanide strike bath at a pH in the range of 8.5-11.0, using a current density in the range of 0.1-10 A/dm2. The pretreatment and electroplating steps are preferably conducted by barrel plating, in accordance with another aspect of the invention. the ratio Ir/Is of the remanent magnetization Ir to the saturation magnetization Is is 0.6 or more. 6. A hard magnetic alloy according to claim 1, wherein said hard magnetic alloy has the following formula: TxMyRzBw wherein T represents at least one element selected from the group consisting of Fe, Co and Ni, M represents at least one element selected from the group consisting of Zr, Nb, Ta and Hf, R represents at least one rare earth element, and the suffixes x, y, z and w by atomic percent satisfy 50≤x, 0≤y≤15, 3≤z≤20, and 2≤w≤20, respectively. 7. A hard magnetic alloy according to claim 6, wherein the suffixes x, y, z and w by atomic percent satisfy 80≤x≤92, 1≤y≤5, 3≤z≤10, and 3≤w≤7, respectively. 8. A hard magnetic alloy according to claim 1, wherein said hard magnetic alloy has the following formula: TxMyRzBwSiu wherein T represents at least one element selected from the group consisting of Fe, Co and Ni, M represents at least one element selected from the group consisting of Zr, Nb, Ta and Hf, R represents at least one rare earth element, and the suffixes x, y, z, w, and u by atomic percent satisfy 50≤x, 0≤y≤15, 3≤z≤20, 2≤w≤20, and 0≤u≤5, respectively. 9. A hard magnetic alloy according to claim 8, wherein the suffixes x, y, z, w, and u by atomic percent satisfy 80≤x≤92, 1≤y≤5, 3≤z≤10, 3≤w≤7, and 0.5≤u≤5, respectively. 10. A hard magnetic alloy according to claim 1, wherein said hard magnetic alloy has the following formula: TxMyRzBwEv wherein T represents at least one element selected from the group consisting of Fe, Co and Ni, M represents at least one element selected from the group consisting of Zr, Nb, Ta and Hf, R represents at least one rare earth element, E represents at least one element selected from the group consisting of Cr, Al, Pt, Rh, Ru, Pd, Os, and Ir, and the suffixes x, y, z, w, and v by atomic percent satisfy 50≤x, 0≤y≤15, 3≤z≤20, 2≤w≤20, and 0≤v≤10, respectively. 11. A hard magnetic alloy according to claim 10, wherein the suffixes x, y, z, w, and v by atomic percent satisfy 80≤x≤92, 1≤y≤5, 3≤z≤10, 3≤w≤7, and 0≤v≤5, respectively. 12. A hard magnetic alloy according to claim 1, wherein said hard magnetic alloy has the following formula: TxMyRzBwEvSiu wherein T represents at least one element selected from the group consisting of Fe, Co and Ni, M represents at least one element selected from the group consisting of Zr, Nb, Ta and Hf, R represents at least one rare earth element, E represents at least one element selected from the group consisting of Cr, Al, Pt, Rh, Ru, Pd, Os, and Ir, and the suffixes x, y, z, w, v, and u by atomic percent satisfy 50≤x, 0≤y≤15, 3≤z≤20, 2≤w≤20, 0≤v≤10, and 0≤u≤5, respectively. 13. A hard magnetic alloy according to claim 12, wherein the suffixes x, y, z, w, v, and u by atomic percent satisfy 80≤x≤92, 1≤y≤5, 3≤z≤10, 3≤w≤7, 0≤v≤5, and 0.5≤u≤5, respectively. 14. A method for producing a hard magnetic alloy comprising: preparing an alloy containing at least one element T selected from the group consisting of Fe, Co and Ni, at least one rare earth element R, and B, and essentially consisting of an amorphous phase by a liquid quenching process; and annealing said alloy at a heating rate of at least 10° C./min., wherein said alloy to be annealed essentially consisting of said amorphous phase has the following formula: TxMyRzBw wherein T represents at least one element selected from the group consisting of Fe, Co and Ni, M represents at least one element selected from the group consisting of Zr, Nb, Ta and Hf, R represents at least one rare earth element, and the suffixes x, y, z and w by atomic percent satisfy 50≤x, 0≤y≤15, 3 �≤20, and 2≤w≤20, respectively. 15. A method for producing a hard magnetic alloy according to claim 14, wherein the suffixes x, y, z and w by atomic percent satisfy 80≤x≤92, 1≤y≤5, 3≤z≤10, and 3≤w≤7, respectively. 16. A method for producing a hard magnetic alloy comprising: preparing an alloy containing at least one element T selected from the group consisting of Fe, Co and Ni, at least one rare earth element R, and B, and essentially consisting of an amorphous phase by a liquid quenching process; and annealing said alloy at a heating rate of at least 10° C./min., wherein said alloy to be annealed essentially consisting of said amorphous phase has the following formula: TxMyRzBwSiu wherein T represents at least one element selected from the group consisting of Fe, Co and Ni, M represents at least one element selected from the group consisting of Zr, Nb, Ta and Hf, R represents at least one rare earth element, and the suffixes x, y, z, w, and u by atomic percent satisfy 50≤x, 0≤y≤15, 3≤z≤20, 2≤w≤20, and 0≤u≤5, respectively. 17. A method for producing a hard magnetic alloy according to claim 16, wherein the suffixes x, y, z, w, and u by atomic percent satisfy 80≤x≤92, 1≤y≤5, 3≤z≤10, 3≤w≤7, and 0.5≤u≤5, respectively. 18. A method for producing a hard magnetic alloy comprising: preparing an alloy containing at least one element T selected from the group consisting of Fe, Co and Ni, at least one rare earth element R, and B, and essentially consisting of an amorphous phase by a liquid quenching process; and annealing said alloy at a heating rate of at least 10° C./min., wherein said alloy to be annealed essentially consisting of said amorphous phase has the following formula: TxMyRzBwEv wherein T represents at least one element selected from the group consisting of Fe, Co and Ni, M represents at least one element selected from the group consisting of Zr, Nb, Ta and Hf, R represents at least one rare earth element, E represents at least one element selected from the group consisting of Cr, Al, Pt, Rh, Ru, Pd, Os, and Ir, and the suffixes x, y, z, w, and v by atomic percent satisfy 50≤x, 0≤y≤15, 3≤z≤20, 2≤w≤20, and 0≤v≤10, respectively. 19. A method for producing a hard magnetic alloy according to claim 18, wherein the suffixes x, y, z, w, and v by atomic percent satisfy 80≤x≤92, 1≤y≤5, 3≤z≤10, 3≤w≤7, and 0≤v≤5, respectively. 20. A method for producing a hard magnetic alloy comprising: preparing an alloy containing at least one element T selected from the group consisting of Fe, Co and Ni, at least one rare earth element R, and B, and essentially consisting of an amorphous phase by a liquid quenching process; and annealing said alloy at a heating rate of at least 10° C./min., wherein said alloy to be annealed essentially consisting of said amorphous phase has the following formula: TxMyRzBwEvSiu wherein T represents at least one element selected from the group consisting of Fe, Co and Ni, M represents at least one element selected from the group consisting of Zr, Nb, Ta and Hf, R represents at least one rare earth element, E represents at least one element selected from the group consisting of Cr, Al, Pt, Rh, Ru, Pd, Os, and Ir, and the suffixes x, y, z, w, v, and u by atomic percent satisfy 50≤x, 0≤y≤15, 3≤z≤20, 2≤w≤20, 0≤v≤10, and 0≤u≤5, respectively. 21. A method for producing a hard magnetic alloy according to claim 20, wherein the suffixes x, y, z, w, v, and u by atomic percent satisfy 80≤x≤92, 1≤y≤5, 3≤z≤10, 3≤w≤7, 0≤v≤5, and 0.5≤u≤5, respectively.