Development of burn-resistant titanium alloys is the most direct way of mitigating the ignition and propagation of titanium fires in jet engines. WSTi3515S alloy（Ti–35V–15Cr–0.3Si–0.1C） is a new high alloying be...Development of burn-resistant titanium alloys is the most direct way of mitigating the ignition and propagation of titanium fires in jet engines. WSTi3515S alloy（Ti–35V–15Cr–0.3Si–0.1C） is a new high alloying beta type burn-resistant titanium alloy, belonging to Ti–V–Cr type alloys which have been made significant progress in engineering technology in the past 5 years. The physical properties of WSTi3515S burn-resistant titanium alloy such as the elastic properties and thermal properties were measured and analyzed in different conditions. The results show that both the Young＇s modulus and shear modulus of WSTi3515S alloy decrease slightly with the temperature increasing at the tested temperature range. The Poisson＇s ratio of WSTi3515S alloy is around 0.36. However, the thermal properties such as the specific heat, thermal diffusivity, thermal conductivity and thermal expansion increase with the temperature increasing, which results from the strengthening of lattice heat vibration at elevated temperature. And the room temperature density of WSTi3515S alloy is 5.295 gácm^（-3）.展开更多
Copper was diffused on the surface of titanium alloy Ti6Al4V by ion implantation,magnetron sputtering and double glow discharge plasma surface alloying technology respectively to form an alloy layer on the surface of ...Copper was diffused on the surface of titanium alloy Ti6Al4V by ion implantation,magnetron sputtering and double glow discharge plasma surface alloying technology respectively to form an alloy layer on the surface of titanium alloy in order to improve the burn-resistance performance of titanium alloy.The result of X-Ray Diffraction shows that the phase of CuTi2 which can improve the burn-resistance performance can be found on the surface of the samples treated by the above three methods.And femtosecond laser ablation experiments show that the burn-resistance property of the titanium alloy can be enhanced by ion implantation,but the alloyed layer is too thin to be applied in practice;both of alloy layer and film can be formed on the surface of titanium alloy by magnetron sputtering,the alloy layer takes evident effect on the burn-resistance properties of titanium alloy while the film has no effect on the burn-resistant properties;alloy layer with Cu can be found on the surface of titanium alloy by the double glow plasma surface alloying technology with the source of pure copper,and its effect on burn-resistance properties of the titanium alloy is evident as the scar area by the laser burning experiment has been reduced heavily.展开更多
The combustion behavior of Ti-Al-Mo-Zr-Sn-W alloy(TC25G)was studied in a high-temperature and high-speed air flow environment using the laser ignition method combined with ultra-high temperature infrared thermometer,s...The combustion behavior of Ti-Al-Mo-Zr-Sn-W alloy(TC25G)was studied in a high-temperature and high-speed air flow environment using the laser ignition method combined with ultra-high temperature infrared thermometer,scanning electron microscope,X-ray diffractometer,and transmission electron microscope.The burn-resistant performance of TC25G and TC11 alloys was compared.Meanwhile,the microstructural characteristics,crystal structure,and formation mechanism of the combustion products of TC25G alloy were analyzed in detail.The results show that the high-temperature and high-speed air flow promotes combustion within the air flow temperature range of 200–400℃and the air flow velocity range of 0–100 m/s.The combustion path advances along the direction of the air flow.The combustion of TC25G alloy mainly relies on the diffusion of the oxygen and the expansion of the combustion area caused by the movement of the melt.Based on the microstructure and composition of combustion product,it can be divided into the combustion zone,the melting zone,and the heat affected zone.During combustion,the formation of microstructures is closely correlated with the behavior of alloying elements and their selective combination with O.The major oxidation products of Ti are TiO and TiO_(2).The oxides formed by Mo and W hinder the movement of the melt during the combustion.Al and Zr tend to undergo internal oxidation.Al_(2)O_(3)precipitates on the surface of ZrO_(2),forming a protective oxide layer that inhibits the inward diffusion of O.Moreover,the element enrichment at the interface between the melting zone and the heat affected zone increases the melting point on the solid side,hindering the migration of the solid-liquid interface.展开更多
基金financially supported by the International Science and Technology Cooperation Program of China (No. ISTCP 2013DFR50090)the National Natural Science Foundation of China (No. 51504037)the Special Fund for Basic Scientific Research of Central Colleges,Chang’an University (No. 2014G1311088)
文摘Development of burn-resistant titanium alloys is the most direct way of mitigating the ignition and propagation of titanium fires in jet engines. WSTi3515S alloy（Ti–35V–15Cr–0.3Si–0.1C） is a new high alloying beta type burn-resistant titanium alloy, belonging to Ti–V–Cr type alloys which have been made significant progress in engineering technology in the past 5 years. The physical properties of WSTi3515S burn-resistant titanium alloy such as the elastic properties and thermal properties were measured and analyzed in different conditions. The results show that both the Young＇s modulus and shear modulus of WSTi3515S alloy decrease slightly with the temperature increasing at the tested temperature range. The Poisson＇s ratio of WSTi3515S alloy is around 0.36. However, the thermal properties such as the specific heat, thermal diffusivity, thermal conductivity and thermal expansion increase with the temperature increasing, which results from the strengthening of lattice heat vibration at elevated temperature. And the room temperature density of WSTi3515S alloy is 5.295 gácm^（-3）.
文摘Copper was diffused on the surface of titanium alloy Ti6Al4V by ion implantation,magnetron sputtering and double glow discharge plasma surface alloying technology respectively to form an alloy layer on the surface of titanium alloy in order to improve the burn-resistance performance of titanium alloy.The result of X-Ray Diffraction shows that the phase of CuTi2 which can improve the burn-resistance performance can be found on the surface of the samples treated by the above three methods.And femtosecond laser ablation experiments show that the burn-resistance property of the titanium alloy can be enhanced by ion implantation,but the alloyed layer is too thin to be applied in practice;both of alloy layer and film can be formed on the surface of titanium alloy by magnetron sputtering,the alloy layer takes evident effect on the burn-resistance properties of titanium alloy while the film has no effect on the burn-resistant properties;alloy layer with Cu can be found on the surface of titanium alloy by the double glow plasma surface alloying technology with the source of pure copper,and its effect on burn-resistance properties of the titanium alloy is evident as the scar area by the laser burning experiment has been reduced heavily.
基金China“Ye Qisun”Science Foundation Project of National Natural Science Foundation(U2141222)Innovation Fund(8F231527Z)。
文摘The combustion behavior of Ti-Al-Mo-Zr-Sn-W alloy(TC25G)was studied in a high-temperature and high-speed air flow environment using the laser ignition method combined with ultra-high temperature infrared thermometer,scanning electron microscope,X-ray diffractometer,and transmission electron microscope.The burn-resistant performance of TC25G and TC11 alloys was compared.Meanwhile,the microstructural characteristics,crystal structure,and formation mechanism of the combustion products of TC25G alloy were analyzed in detail.The results show that the high-temperature and high-speed air flow promotes combustion within the air flow temperature range of 200–400℃and the air flow velocity range of 0–100 m/s.The combustion path advances along the direction of the air flow.The combustion of TC25G alloy mainly relies on the diffusion of the oxygen and the expansion of the combustion area caused by the movement of the melt.Based on the microstructure and composition of combustion product,it can be divided into the combustion zone,the melting zone,and the heat affected zone.During combustion,the formation of microstructures is closely correlated with the behavior of alloying elements and their selective combination with O.The major oxidation products of Ti are TiO and TiO_(2).The oxides formed by Mo and W hinder the movement of the melt during the combustion.Al and Zr tend to undergo internal oxidation.Al_(2)O_(3)precipitates on the surface of ZrO_(2),forming a protective oxide layer that inhibits the inward diffusion of O.Moreover,the element enrichment at the interface between the melting zone and the heat affected zone increases the melting point on the solid side,hindering the migration of the solid-liquid interface.
