A-type titanium alloy and its preparation method

Abstract

The present invention provides an α-type titanium alloy, the fracture toughness and thermal creep resistance of the prepared α-type titanium alloy are improved by controlling the content of Al, Zr, and Sn. The room temperature strength is improved by adding a certain amount of Si, and the thermal creep resistance is further improved. The addition of a certain amount of C and Cr improves the high-temperature tensile properties of the prepared α-type titanium alloy. The method provided by the invention has a simple process and low cost and can achieve good matching of low cost, high performance, and less processing capacity. The prepared α-type titanium alloy in example 1˜4 of the invention has an elastic modulus of 124˜132 GPa, a tensile strength of 867˜881 MPa, a yield strength of 743˜762 MPa, an elongation of 22%˜24.0%, and a section shrinkage of 47%˜51% at 600° C.

1 . An α-type titanium alloy, the α-type titanium alloy is composed of following components in mass percentage: Al 8%˜11.0%, Zr 1.3%˜1.8%, Sn 1.5%˜2.8%, Cr 2.2%˜4.5%, Si 0.2%˜0.3%, C 0.03%˜0.05%, and remainder is Ti and inevitable impurity elements, the titanium alloy has an elastic modulus of 127˜132 GPa, a tensile strength of 872˜881 MPa, a yield strength of 747˜762 MPa, an elongation of 22.5%˜24.0%, and a section shrinkage of 46%˜51% at 600° C. 
     
     
         2 . The α-type titanium alloy according to  claim 1 , the α-type titanium alloy is composed of the following components in mass percentage: Al 8%˜10.6%, Zr 1.5%˜1.7%, Sn 1.8%˜2.5%, Cr 2.8%˜4.1%, Si 0.24%˜0.28%, C 0.035%˜0.048%, and the remainder is Ti and unavoidable impurity elements. 
     
     
         3 . The α-type titanium alloy according to  claim 1 , the impurity elements are N and H, and the mass percentage of impurity elements in the α-type titanium alloy is: N≤0.05%, H≤0.01%. 
     
     
         4 . A preparation method for α-type titanium alloy according to  claim 1 , comprising the steps of:
 (1) batching according to the chemical composition of the α-type titanium alloy to obtain a titanium alloy raw material; 
 successively smelting and casting the titanium alloy raw material to obtain an alloy ingot; 
 (2) successively performing blooming and first forging on the alloy ingot obtained in step (1) to obtain a slab; 
 (3) subjecting the slab obtained in the step (2) to successively peeling and grinding, hot rolling, and vacuum annealing to obtain an α-type titanium alloy. 
 
     
     
         5 . The preparation method according to  claim 4 , the melting method in step (1) is vacuum consumable arc melting. 
     
     
         6 . The preparation method according to  claim 4 , the temperature for blooming and forging in the step (2) is independently 950° C.˜1050° C. 
     
     
         7 . The preparation method according to  claim 4 , the temperature of the hot rolling in the step (3) is 890° C.˜960° C. 
     
     
         8 . The preparation method according to  claim 4 , the temperature of the vacuum annealing in the step (3) is 800° C.˜950° C., and the time of the vacuum annealing is 1 h˜4 h. 
     
     
         9 . A preparation method for α-type titanium alloy according to  claim 2 , comprising the steps of:
 (1) batching according to the chemical composition of the α-type titanium alloy to obtain a titanium alloy raw material; 
 successively smelting and casting the titanium alloy raw material to obtain an alloy ingot; 
 (2) successively performing blooming and first forging on the alloy ingot obtained in step (1) to obtain a slab; 
 (3) subjecting the slab obtained in the step (2) to successively peeling and grinding, hot rolling, and vacuum annealing to obtain an α-type titanium alloy. 
 
     
     
         10 . The preparation method according to  claim 9 , the melting method in step (1) is vacuum consumable arc melting. 
     
     
         11 . The preparation method according to  claim 9 , the temperature for blooming and forging in the step (2) is independently 950° C.˜1050° C. 
     
     
         12 . The preparation method according to  claim 9 , the temperature of the hot rolling in the step (3) is 890° C.˜960° C. 
     
     
         13 . The preparation method according to  claim 9 , the temperature of the vacuum annealing in the step (3) is 800° C.˜950° C., and the time of the vacuum annealing is 1 h˜4 h. 
     
     
         14 . A preparation method for α-type titanium alloy according to  claim 3 , comprising the steps of:
 (1) batching according to the chemical composition of the α-type titanium alloy to obtain a titanium alloy raw material; 
 successively smelting and casting the titanium alloy raw material to obtain an alloy ingot; 
 (2) successively performing blooming and first forging on the alloy ingot obtained in step (1) to obtain a slab; 
 (3) subjecting the slab obtained in the step (2) to successively peeling and grinding, hot rolling, and vacuum annealing to obtain an α-type titanium alloy. 
 
     
     
         15 . The preparation method according to  claim 14 , the melting method in step (1) is vacuum consumable arc melting. 
     
     
         16 . The preparation method according to  claim 14 , the temperature for blooming and forging in the step (2) is independently 950° C.˜1050° C. 
     
     
         17 . The preparation method according to  claim 14 , the temperature of the hot rolling in the step (3) is 890° C.˜960° C. 
     
     
         18 . The preparation method according to  claim 14 , the temperature of the vacuum annealing in the step (3) is 800° C.˜950° C., and the time of the vacuum annealing is 1 h˜4 h.