Dampling alloy, process for producing the same, and damping part or vibration-proof product comprising or employing the same

Abstract

A manganese-based damping alloy having stable damping properties; a process by which the damping alloy can be obtained without fail; and a damping part or vibration-proof product comprising or employing the damping alloy. A damping alloy made up of from 16.9 to 27.7 wt% copper, from 2.1 to 8.2 wt% nickel, from 1.0 to 2.9 wt% iron, 0.05 wt% or less carbon, 0.06 wt% or less oxygen, 0.06 wt% or less nitrogen, and manganese and unavoidable impurities as the remainder. Due to this constitution, nonmetallic inclusions such as carbides generate in a reduced amount and the manganese-based alloy can be pure. Consequently, the formation of a twin-crystal structure during heat treatment is accelerated and factors which inhibit the twin-crystal structure from moving upon stress imposition are diminished, whereby damping properties can be improved.

What is claimed is:  
     
         1 . A damping alloy which comprises from 16.9 to 27.7 wt% copper, from 2.1 to 8.2 wt% nickel, from 1.0 to 2.9 wt% iron, 0.05 wt% or less carbon, 0.06 wt% or less oxygen, 0.06 wt% or less nitrogen, and manganese and unavoidable impurities as the remainder.  
     
     
         2 . A process for producing a damping alloy which comprises a step by melting a raw damping-alloy material comprising from 16.9 to 27.7 wt% copper, from 2.1 to 8.2 wt% nickel, from 1.0 to 2.9 wt% iron, and manganese and unavoidable impurities as the remainder at a temperature in the range of from the temperature higher by 50° C. than the melting point of the alloy to 1,480° C. 
 in an inert atmosphere having a partial oxygen pressure of 1,013.25 Pa or lower and a total pressure of 66,661 Pa or higher.  
 
     
     
         3 . The process for producing a damping alloy of  claim 2 , wherein in the melting step, the raw damping-alloy material is charged into a vessel comprising MgO—Al 2 O 3  as a refractory and is melted therein.  
     
     
         4 . A damping part or vibration-proof product which comprises a damping alloy comprising from 16.9 to 27.7 wt% copper, from 2.1 to 8.2 wt% nickel, from 1.0 to 2.9 wt% iron, 0.05 wt% or less carbon, 0.06 wt% or less oxygen, 0.06 wt% or less nitrogen, and manganese and unavoidable impurities as the remainder, said alloy having been formed into a necessary shape.  
     
     
         5 . The damping part of  claim 4 , which is one member selected from the group consisting of machine elements, tools for machining, bases or casings of metal working apparatus, spacers, liners, pipes, radiating plates, valves, engine parts, electronic parts, parts of sports goods, and fasteners for ducts or pipings.  
     
     
         6 . The vibration-proof product of  claim 4 , which is one member selected from the group consisting of conveying apparatus, audio/video appliances, medical machines or apparatus, precision measuring instruments, sensors, transportation machines or apparatus, domestic electrical appliances, industrial machines or apparatus, air-conditioning machines or apparatus, computers, printers, copiers, building materials for openings, opening/closing devices, sports goods, and writing materials.