Ti-600 is one of the high performance titanium alloys used at 600 ℃,which was developed in Northwest Institute for Nonferrous Metal Research(NIN) in China. The tensile and creep properties of Ti-600 alloy with differ...Ti-600 is one of the high performance titanium alloys used at 600 ℃,which was developed in Northwest Institute for Nonferrous Metal Research(NIN) in China. The tensile and creep properties of Ti-600 alloy with different thermal treatment conditions were investigated. The results indicate that Ti-600 alloy possesses favorite comprehensive properties solution-treated at 1 020 ℃ for 1 h,then air-cool,and aged at 650 ℃ for 8 h,finally air-cooling,especially possesses quite good creep resistance. The residual deformation is less than 0.1% for the alloy exposed at 600 ℃ for 100 h with the stress of 150 MPa,and the bimodal microstructures of the alloy are almost the same as that of the alloy treated by duplex thermal treatment,only needle primary α phases became relatively thicker and coarsened. The ultimate strength and the elongation of the alloy tested at ambient temperature are 1 080 MPa and 12%,respectively;while at 600 ℃,they are 690 MPa and 16%,respectively. The ductility of the alloy tested at room temperature is no less than 5% after thermal exposing at 600 ℃ for 100 h.展开更多
The multi-component composition characteristics of high-temperature near-α Ti alloys were investigated in the present work by means of a cluster formula approach. The uniform cluster formula [CN12 cluster](glue atom)...The multi-component composition characteristics of high-temperature near-α Ti alloys were investigated in the present work by means of a cluster formula approach. The uniform cluster formula [CN12 cluster](glue atom)3 for the hexagonal close-packed α solid solution was first obtained based on the Friedel oscillation theory, with a total atom number in the formula of Z = 16. Then it was analyzed that the Z values in the cluster composition formulas of typical near-α Ti alloys are within the range of Z = 16.0016.30, being perfectly consistent with the ideal Z = 16. Based on it, a series of new alloys with Z = 16 and with Nb/Ta substitution for Mo in Ti1100 alloy were designed, suction-cast into φ 6 mm rods, and then heat-treated with solid solution and aging. It was found that the alloy with co-addition of Mo, Ta and Nb has a high strength and good ductility at both room and high temperatures. More importantly, the additions of Nb and Ta can contribute to the formation of continuous and compact Al2O3 scales, resulting in an obvious improvement of oxidation resistances at both 923 K and 1073 K. The effects of Mo, Ta and Nb on the oxidation behaviors of the designed alloys at 1073 K were further discussed.展开更多
基金Projects(2007CB613805) supported by the National Basic Research Program of China
文摘Ti-600 is one of the high performance titanium alloys used at 600 ℃,which was developed in Northwest Institute for Nonferrous Metal Research(NIN) in China. The tensile and creep properties of Ti-600 alloy with different thermal treatment conditions were investigated. The results indicate that Ti-600 alloy possesses favorite comprehensive properties solution-treated at 1 020 ℃ for 1 h,then air-cool,and aged at 650 ℃ for 8 h,finally air-cooling,especially possesses quite good creep resistance. The residual deformation is less than 0.1% for the alloy exposed at 600 ℃ for 100 h with the stress of 150 MPa,and the bimodal microstructures of the alloy are almost the same as that of the alloy treated by duplex thermal treatment,only needle primary α phases became relatively thicker and coarsened. The ultimate strength and the elongation of the alloy tested at ambient temperature are 1 080 MPa and 12%,respectively;while at 600 ℃,they are 690 MPa and 16%,respectively. The ductility of the alloy tested at room temperature is no less than 5% after thermal exposing at 600 ℃ for 100 h.
基金financially supported by the National Key Research and Development Plan(No.2017YFB0702400)the Science Challenge Project(No.TZ2016004)+1 种基金the National Magnetic Confinement Fusion Energy Research Project(No.2015GB121004)the Foundation of Guangxi Key Laboratory of Information Materials(No.161002-K)
文摘The multi-component composition characteristics of high-temperature near-α Ti alloys were investigated in the present work by means of a cluster formula approach. The uniform cluster formula [CN12 cluster](glue atom)3 for the hexagonal close-packed α solid solution was first obtained based on the Friedel oscillation theory, with a total atom number in the formula of Z = 16. Then it was analyzed that the Z values in the cluster composition formulas of typical near-α Ti alloys are within the range of Z = 16.0016.30, being perfectly consistent with the ideal Z = 16. Based on it, a series of new alloys with Z = 16 and with Nb/Ta substitution for Mo in Ti1100 alloy were designed, suction-cast into φ 6 mm rods, and then heat-treated with solid solution and aging. It was found that the alloy with co-addition of Mo, Ta and Nb has a high strength and good ductility at both room and high temperatures. More importantly, the additions of Nb and Ta can contribute to the formation of continuous and compact Al2O3 scales, resulting in an obvious improvement of oxidation resistances at both 923 K and 1073 K. The effects of Mo, Ta and Nb on the oxidation behaviors of the designed alloys at 1073 K were further discussed.
文摘研究了经α+β两相区固溶+时效处理的Ti-600合金3种温度(550、600、650℃)、3种应力(250、300、350 MPa)下的蠕变性能,通过合金的稳态蠕变速率数值求解了合金的蠕变激活能和蠕变应力指数n,并引入临界应力σ0获得合金的真实应力指数p,最后对合金的蠕变机制进行了分析。结果表明,蠕变温度升高、蠕变应力增加时,Ti-600合金的稳态蠕变速率增大,稳态蠕变时间缩短。Ti-600合金的名义蠕变激活能为473.5 k J/mol。600和650℃下,合金的临界应力σ0值分别为103.1和42.1 MPa;应力指数n分别为6.5和4.9;真实应力指数p值分别为4.23和4.22。同时构建了该合金600和650℃下的稳态蠕变速率本构方程。本实验条件下合金的蠕变均为位错攀移机制。
