Materials-development projects for advanced ultra-supercritical(A-USC) power plants with steam temperatures of 700℃ and above have been performed in order to achieve high efficiency and low CO_2 emissions in Europe, ...Materials-development projects for advanced ultra-supercritical(A-USC) power plants with steam temperatures of 700℃ and above have been performed in order to achieve high efficiency and low CO_2 emissions in Europe, the US, Japan, and recently in China and India as well. These projects involve the replacement of martensitic 9%–12% Cr steels with nickel(Ni)-base alloys for the highest temperature boiler and turbine components in order to provide sufficient creep strength at 700℃ and above. To minimize the requirement for expensive Ni-base alloys, martensitic 9%–12% Cr steels can be applied to the next highest temperature components of an A-USC power plant, up to a maximum of 650℃. This paper comprehensively describes the research and development of Ni-base alloys and martensitic 9%–12% Cr steels for thick section boiler and turbine components of A-USC power plants, mainly focusing on the long-term creep-rupture strength of base metal and welded joints, strength loss in welded joints, creep-fatigue properties, and microstructure evolution during exposure at elevated temperatures.展开更多
The fatigue property of AZ31 magnesium alloy and its TIG welded joints were investigated. The ultrasonic peening treatment （UPT） was used to improve the fatigue property of the TIG welded joints, which was treated a...The fatigue property of AZ31 magnesium alloy and its TIG welded joints were investigated. The ultrasonic peening treatment （UPT） was used to improve the fatigue property of the TIG welded joints, which was treated at the weld toe by the UPT process. The test results show that the fatigue strength of the base metal of AZ31 magnesium alloys is 57.8 MPa, and those of the fillet joint and the transverse cross joint are respectively 20. 0 MPa and 17.2 MPa at 2 × 10^6 cycles. The fatigue strengths of two kinds of welded joints treated by the UPT are respectively 30. 3 MPa and 24. 7 MPa, which have been improved by 51.5% and 43.6%, respectively. The fatigue life of the fillet joint specimens is prolonged by about 2. 74 times and the fatigue life of the transverse cross joint specimens is prolonged by about 1.05 times when the stress range is at 40. 0 MPa.展开更多
对锌铝合金的钎焊性进行了分析,对ZnCl2 NH4Cl KF钎剂的去膜机理以及Cd Sn Zn钎料各组分的作用进行了阐述;分析了锌铝合金钎焊接头的力学性能、组织和成分;并对钎焊接头进行了无损检测。试验结果表明:用自制的Cd Sn Zn钎料和ZnCl2 NH4Cl...对锌铝合金的钎焊性进行了分析,对ZnCl2 NH4Cl KF钎剂的去膜机理以及Cd Sn Zn钎料各组分的作用进行了阐述;分析了锌铝合金钎焊接头的力学性能、组织和成分;并对钎焊接头进行了无损检测。试验结果表明:用自制的Cd Sn Zn钎料和ZnCl2 NH4Cl KF钎剂,经320℃加热和15min保温,对锌铝合金进行炉中钎焊,其钎焊接头抗拉强度为116.3MPa,抗剪强度为96MPa;接头中生成了新相,存在着(220)Mg2Cu6Al5//(010)Cd的相结构。展开更多
背景:发育性髋关节发育不良患者常有一个浅髋臼、笔直狭窄的股骨管等解剖结构的广泛扭曲,尤其是面对高度脱位的发育性髋关节发育不良患者,实施手术治疗时具有很大的挑战性。近年来,3D打印多孔钽金属个体化治疗发育性髋关节发育不良的效...背景:发育性髋关节发育不良患者常有一个浅髋臼、笔直狭窄的股骨管等解剖结构的广泛扭曲,尤其是面对高度脱位的发育性髋关节发育不良患者,实施手术治疗时具有很大的挑战性。近年来,3D打印多孔钽金属个体化治疗发育性髋关节发育不良的效果及预后较好,可用于术前诊断、术前手术规划、术中建立3D导航模板、明确术前髋臼严重程度及术后髋臼重建矫正评估,具有良好的发展前景。目的:探讨3D打印多孔钽金属治疗髋关节发育不良的最新研究进展。方法:采用计算机检索中国知网、PubMed、MDPI、BMC Biotechnology、Web of Science和Springer link数据库中有关3D打印多孔钽金属个体化治疗发育性髋关节发育不良的研究资料,检索时限为1970-2022年。根据纳入和排除标准,最终共选取58篇文献进行综述。结果与结论:(1)多孔钽金属主要有生物兼容性、骨整合性和骨诱导性等生物学特性及生物力学特性,有效地促进了新骨、新的血管及神经的良好生长。(2)3D打印多孔钽金属是由3D打印成型技术、天然金属材料-多孔钽金属联合运用方案,目前主要在发育性髋关节发育不良及髋关节骨缺损患者中评价这一方案的有效性。(3)3D打印多孔钽金属良好的术前计划能有效改善发育性髋关节发育不良、髋关节骨缺损的术后效果,并为假体植入物做好术前个体化规划的准备,能有效避免术中障碍和充分解决患者特异性畸形,直接影响手术结果,应用前景较好。(4)目前,应用3D打印多孔钽金属个体化治疗发育性髋关节发育不良的短期疗效在动物模型及部分文献中得到验证,但缺乏中长期随访结果。展开更多
文摘Materials-development projects for advanced ultra-supercritical(A-USC) power plants with steam temperatures of 700℃ and above have been performed in order to achieve high efficiency and low CO_2 emissions in Europe, the US, Japan, and recently in China and India as well. These projects involve the replacement of martensitic 9%–12% Cr steels with nickel(Ni)-base alloys for the highest temperature boiler and turbine components in order to provide sufficient creep strength at 700℃ and above. To minimize the requirement for expensive Ni-base alloys, martensitic 9%–12% Cr steels can be applied to the next highest temperature components of an A-USC power plant, up to a maximum of 650℃. This paper comprehensively describes the research and development of Ni-base alloys and martensitic 9%–12% Cr steels for thick section boiler and turbine components of A-USC power plants, mainly focusing on the long-term creep-rupture strength of base metal and welded joints, strength loss in welded joints, creep-fatigue properties, and microstructure evolution during exposure at elevated temperatures.
基金the National Natural Science Foundation of China (No.50675148)
文摘The fatigue property of AZ31 magnesium alloy and its TIG welded joints were investigated. The ultrasonic peening treatment （UPT） was used to improve the fatigue property of the TIG welded joints, which was treated at the weld toe by the UPT process. The test results show that the fatigue strength of the base metal of AZ31 magnesium alloys is 57.8 MPa, and those of the fillet joint and the transverse cross joint are respectively 20. 0 MPa and 17.2 MPa at 2 × 10^6 cycles. The fatigue strengths of two kinds of welded joints treated by the UPT are respectively 30. 3 MPa and 24. 7 MPa, which have been improved by 51.5% and 43.6%, respectively. The fatigue life of the fillet joint specimens is prolonged by about 2. 74 times and the fatigue life of the transverse cross joint specimens is prolonged by about 1.05 times when the stress range is at 40. 0 MPa.
文摘对锌铝合金的钎焊性进行了分析,对ZnCl2 NH4Cl KF钎剂的去膜机理以及Cd Sn Zn钎料各组分的作用进行了阐述;分析了锌铝合金钎焊接头的力学性能、组织和成分;并对钎焊接头进行了无损检测。试验结果表明:用自制的Cd Sn Zn钎料和ZnCl2 NH4Cl KF钎剂,经320℃加热和15min保温,对锌铝合金进行炉中钎焊,其钎焊接头抗拉强度为116.3MPa,抗剪强度为96MPa;接头中生成了新相,存在着(220)Mg2Cu6Al5//(010)Cd的相结构。
文摘背景:发育性髋关节发育不良患者常有一个浅髋臼、笔直狭窄的股骨管等解剖结构的广泛扭曲,尤其是面对高度脱位的发育性髋关节发育不良患者,实施手术治疗时具有很大的挑战性。近年来,3D打印多孔钽金属个体化治疗发育性髋关节发育不良的效果及预后较好,可用于术前诊断、术前手术规划、术中建立3D导航模板、明确术前髋臼严重程度及术后髋臼重建矫正评估,具有良好的发展前景。目的:探讨3D打印多孔钽金属治疗髋关节发育不良的最新研究进展。方法:采用计算机检索中国知网、PubMed、MDPI、BMC Biotechnology、Web of Science和Springer link数据库中有关3D打印多孔钽金属个体化治疗发育性髋关节发育不良的研究资料,检索时限为1970-2022年。根据纳入和排除标准,最终共选取58篇文献进行综述。结果与结论:(1)多孔钽金属主要有生物兼容性、骨整合性和骨诱导性等生物学特性及生物力学特性,有效地促进了新骨、新的血管及神经的良好生长。(2)3D打印多孔钽金属是由3D打印成型技术、天然金属材料-多孔钽金属联合运用方案,目前主要在发育性髋关节发育不良及髋关节骨缺损患者中评价这一方案的有效性。(3)3D打印多孔钽金属良好的术前计划能有效改善发育性髋关节发育不良、髋关节骨缺损的术后效果,并为假体植入物做好术前个体化规划的准备,能有效避免术中障碍和充分解决患者特异性畸形,直接影响手术结果,应用前景较好。(4)目前,应用3D打印多孔钽金属个体化治疗发育性髋关节发育不良的短期疗效在动物模型及部分文献中得到验证,但缺乏中长期随访结果。
