Cu-AI-Mn-BASED ALLOY ROD AND SHEET EXHIBITING STABLE SUPERELASTICITY, METHOD OF PRODUCING THE SAME, VIBRATION DAMPING MATERIAL USING THE SAME, AND VIBRATION DAMPING STRUCTURE CONSTRUCTED BY USING VIBRATION DAMPING MATERIAL

Abstract

A Cu—Al—Mn-based alloy rod having superelastic characteristics and having a recrystallized microstructure substantially formed of a β single phase, wherein, for a longitudinal direction cross section of the rod, a region, in which a grain size of each of grains is a radius of the rod or more, is 90% or more of the longitudinal direction cross section at any location of the rod, and wherein an average grain size of the grains, in which the grain size is the radius of the rod or more, is 80% or more of a diameter of the rod; a Cu—Al—Mn-based alloy sheet; a production method thereof; a vibration damping material using thereof; a vibration damping structure constructed by using the vibration damping material.

1 . A Cu—Al—Mn-based alloy rod having superelastic characteristics and having a recrystallized microstructure substantially formed of a β single phase,
 wherein, for a longitudinal direction cross section of the rod, a region, in which a grain size of each of grains is a radius of the rod or more, is 90% or more of the longitudinal direction cross section at any location of the rod, and wherein an average grain size of the grains, in which the grain size is the radius of the rod or more, is 80% or more of a diameter of the rod. 
 
     
     
         2 . The Cu—Al—Mn-based alloy rod as claimed in  claim 1 , wherein the average grain size is the diameter of the rod or more. 
     
     
         3 . The Cu—Al—Mn-based alloy rod as claimed in  claim 1 , wherein the Cu—Al—Mn-based alloy has a composition containing 3 to 10 mass % of Al; 5 to 20 mass % of Mn; optionally 1 mass % or less of Ni; and optionally 0.001 to 10 mass % in total of at least one element selected from the group consisting of Co, Fe, Ti, V, Cr, Si, Nb, Mo, W, Sn, Mg, P, Be, Sb, Cd, As, Zr, Zn, and Ag, with the balance being Cu and unavoidable impurities. 
     
     
         4 . A method of producing a Cu—Al—Mn-based alloy rod having a composition containing 3 to 10 mass % of Al, 5 to 20 mass % of Mn, optionally 1 mass % or less of Ni; and optionally 0.001 to 10 mass % in total of at least one element selected from the group consisting of Co, Fe, Ti, V, Cr, Si, Nb, Mo, W, Sn, Mg, P, Be, Sb, Cd, As, Zr, Zn, and Ag, with the balance being Cu and unavoidable impurities, comprising through [Step  1 ] to [Step  3 ], in this order:
 melting and casting an alloy material which gives the composition [Step  1 ]; 
 subjecting to hot working [Step  2 ]; and 
 performing memory heat treatment [Step  3 ], 
 wherein, for the memory heat treatment [Step  3 ], heating is carried out from a room temperature to a temperature range to be a β phase [Step  3 - 1 ]; heating for maintaining the heating temperature for 1 to 120 minutes; and then, cooling [Step  3 - 2 ] and heating [Step  3 - 3 ] are each repeated once or more; heating is carried out, in which the cooling [Step  3 - 2 ] and the heating [Step  3 - 3 ] are set to a temperature to be an α+β phase at a low temperature and are set to a temperature to be a β phase at a high temperature, and in which a cooling speed and a temperature-raising speed at the time of the cooling [Step  3 - 2 ] and the heating [Step  3 - 3 ] are respectively set to 0.1 to 100° C./minute; and, after final heating, heating for quenching from the temperature to be the β phase [Step  3 - 4 ] is carried out. 
 
     
     
         5 . The method of producing a Cu—Al—Mn-based alloy rod as claimed in  claim 4 , wherein, after the subjecting to hot working [Step  2 ], intermediate annealing that is carried out at 400 to 600° C. for 1 to 120 minutes [Step  2 - 1 ] and cold-working at a working ratio of 30% or more [Step  2 - 2 ] are carried out at least one time each in this order, and then, the memory heat treatment [Step  3 ] is carried out. 
     
     
         6 . A vibration damping material being composed of the Cu—Al—Mn-based alloy rod as claimed in  claim 1 . 
     
     
         7 . A vibration damping structure constructed of the vibration damping material as claimed in  claim 6 . 
     
     
         8 . A Cu—Al—Mn-based alloy sheet having superelastic characteristics and having a recrystallized microstructure substantially formed of a β single phase,
 wherein, for a cross section of a sheet thickness direction and a longitudinal direction of the sheet, a region, in which a grain size of each of grains is a half of a sheet thickness or more, is 90% or more of the cross section of the sheet thickness direction and the longitudinal direction at any location of the sheet, and wherein an average grain size of the grains, in which the grain size is the half of the sheet thickness or more, is 80% or more of the sheet thickness. 
 
     
     
         9 . The Cu—Al—Mn-based alloy sheet as claimed in  claim 8 , wherein the average grain size is the sheet thickness or more. 
     
     
         10 . The Cu—Al—Mn-based alloy sheet as claimed in  claim 8 , wherein the Cu—Al—Mn-based alloy has a composition containing 3 to 10 mass % of Al; 5 to 20 mass % of Mn; optionally 1 mass % or less of Ni; and optionally 0.001 to 10 mass % in total of at least one element selected from the group consisting of Co, Fe, Ti, V, Cr, Si, Nb, Mo, W, Sn, Mg, P, Be, Sb, Cd, As, Zr, Zn, and Ag, with the balance being Cu and unavoidable impurities. 
     
     
         11 . A method of producing a Cu—Al—Mn-based alloy sheet having a composition containing 3 to 10 mass % of Al, 5 to 20 mass % of Mn, optionally 1 mass % or less of Ni; and optionally 0.001 to 10 mass % in total of at least one element selected from the group consisting of Co, Fe, Ti, V, Cr, Si, Nb, Mo, W, Sn, Mg, P, Be, Sb, Cd, As, Zr, Zn, and Ag, with the balance being Cu and unavoidable impurities, comprising through [Step  1 ] to [Step  3 ], in this order:
 melting and casting an alloy material which gives the composition [Step  1 ]; 
 subjecting to hot working [Step  2 ]; and 
 performing a memory heat treatment [Step  3 ], 
 wherein, for the memory heat treatment [Step  3 ], heating is carried out from a room temperature to a temperature range to be a β phase [Step  3 - 1 ]; heating for maintaining the heating temperature for 1 to 120 minutes; and then, cooling [Step  3 - 2 ] and heating [Step  3 - 3 ] are each repeated once or more; heating is carried out, in which the cooling [Step  3 - 2 ] and the heating [Step  3 - 3 ] are set to a temperature to be an α+β phase at a low temperature and are set to a temperature to be a β phase at a high temperature, and in which a cooling speed and a temperature-raising speed at the time of the cooling [Step  3 - 2 ] and the heating [Step  3 - 3 ] are respectively set to 0.1 to 100° C./minute; and, after final heating, heating for quenching from the temperature to be the β phase [Step  3 - 4 ] is carried out. 
 
     
     
         12 . The method of producing a Cu—Al—Mn-based alloy sheet as claimed in  claim 11 , wherein, after the subjecting to the hot working [Step  2 ], intermediate annealing that is carried out at 400 to 600° C. for 1 to 120 minutes [Step  2 - 1 ] and cold-working at a working ratio of 30% or more [Step  2 - 2 ] are carried out at least one time each in this order, and then, the memory heat treatment [Step  3 ] is carried out. 
     
     
         13 . A vibration damping material being composed of the Cu—Al—Mn-based alloy sheet as claimed in  claim 8 . 
     
     
         14 . A vibration damping structure constructed of the vibration damping material as claimed in  claim 13 .