Low-density alloy and fabrication method thereof

Abstract

A low-density alloy and the fabrication method thereof are disclosed. The alloy comprises, in weight percent, equal to or greater than 15 wt. % but lower than or equal to 22.5 wt. % manganese, equal to or greater than 7.2 wt. % but lower than or equal to 9.0 wt. % aluminum, equal to or greater than 5.1 wt. % but lower than or equal to 7.8 wt. % chromium, equal to or greater than 0.6 wt. % but lower than or equal to 1.2 wt. % carbon and the balance of iron. The golf-club head made from the abovementioned alloy can obtain superior elongation, strength, damping capacity, and corrosion resistance even without any hot/cold working process, such as forging, rolling, etc.; therefore, the fabrication cost thereof can be obviously reduced.

1 . A low-density alloy comprising greater than or equal to 15 wt. % but lower than or equal to 22.5 wt. % manganese, greater than or equal to 7.2 wt. % but lower than or equal to 9.0 wt. % aluminum, greater than or equal to 5.1 wt. % but lower than or equal to 7.8 wt. % chromium, greater than or equal to 0.6 wt. % but lower than or equal to 1.2 wt. % carbon and the balance of iron. 
     
     
         2 . A low-density alloy according to  claim 1 , further comprising 1.5 wt. % molybdenum at most. 
     
     
         3 . A low-density alloy according to  claim 1 , further comprising 0.7 wt. % silicon at most. 
     
     
         4 . A low-density alloy according to  claim 2 , further comprising 0.7 wt. % silicon at most. 
     
     
         5 . A low-density alloy according to  claim 1 , having a density in a range from 6.6 to 6.9 g/cm 3 , an elongation in a range from 30 to 77% and a tensile strength in a range from 100 to 140 ksi. 
     
     
         6 . A fabrication method of a low-density alloy, including melting a raw material, which comprises greater than or equal to 15 wt. % but lower than or equal to 22.5 wt. % manganese, greater than or equal to 7.2 wt. % but lower than or equal to 9.0 wt. % aluminum, greater than or equal to 5.1 wt. % but lower than or equal to 7.8 wt. % chromium, greater than or equal to 0.6 wt. % but lower than or equal to 1.2 wt. % carbon and the balance of iron, to form an alloy. 
     
     
         7 . A fabrication method of a low-density alloy according to claim  6 , wherein said raw material further comprises 1.5 wt. % molybdenum at most. 
     
     
         8 . A fabrication method of a low-density alloy according to  claim 7 , wherein said raw material further comprises 0.7 wt. % silicon at most. 
     
     
         9 . A fabrication method of a low-density alloy according to  claim 8 , further including a step of heat-treating said alloy at a temperature in a range from 950 to 1200° C. for a duration in an interval from 0.5 to 10 hours, and then at a temperature in a range from 500 to 700° C. for a duration up to a limit of 10 hours. 
     
     
         10 . A fabrication method of a low-density alloy according to  claim 7 , further including a step of heat-treating said alloy at a temperature in a range from 950 to 1200° C. for a duration in an interval from 0.5 to 10 hours, and then at a temperature in a range from 500 to 700° C. for a duration up to a limit of 10 hours. 
     
     
         11 . A fabrication method of a low-density alloy according to  claim 6 , wherein said raw material further comprises 0.7 wt. % silicon at most. 
     
     
         12 . A fabrication method of a low-density alloy according to  claim 11 , further including a step of heat treating said alloy at a temperature in a range from 950 to 1200° C. for a duration in an interval from 0.5 to 10 hours, and then at a temperature in a range from 500 to 700° C. for a duration up to a limit of 10 hours. 
     
     
         13 . A fabrication method of a low-density alloy according to  claim 6 , further including a step of heat-treating said alloy at a temperature in a range from 950 to 1200° C. for a duration in an interval from 0.5 to 10 hours, and then at a temperature in a range from 500 to 700° C. for a duration up to a limit of 10 hours. 
     
     
         14 . A fabrication method of a low-density alloy according to  claim 6 , wherein said step of melting said raw material is an atmosphere melting, a vacuum melting, or a reducing atmosphere melting. 
     
     
         15 . A fabrication method of a low-density alloy according to  claim 6 , wherein said alloy has a density in a range from 6.6 to 6.9 g/cm 3 , an elongation in a range from 30% to 77% and a tensile strength in a range from 100 ksi to 140 ksi.