首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   219篇
  国内免费   11篇
  完全免费   21篇
  金属工艺   166篇
  一般工业技术   57篇
  综合类   7篇
  化学工业   6篇
  冶金工业   6篇
  机械仪表   5篇
  无线电   2篇
  武器工业   1篇
  原子能技术   1篇
  2019年   1篇
  2018年   2篇
  2017年   4篇
  2016年   2篇
  2015年   3篇
  2014年   7篇
  2013年   1篇
  2012年   11篇
  2011年   11篇
  2010年   12篇
  2009年   13篇
  2008年   15篇
  2007年   12篇
  2006年   20篇
  2005年   7篇
  2004年   13篇
  2003年   12篇
  2002年   5篇
  2001年   16篇
  2000年   8篇
  1999年   14篇
  1998年   30篇
  1997年   11篇
  1996年   6篇
  1995年   5篇
  1994年   6篇
  1993年   1篇
  1992年   2篇
  1990年   1篇
排序方式: 共有251条查询结果,搜索用时 31 毫秒
1.
航空航天用新型钛合金的研究发展及应用   总被引:52,自引:9,他引:43  
钱九红 《稀有金属》2000,24(3):218-223
从高强高韧β型钛合金(Ti1023,Ti153,β21S,SP-700和BT-22)、高温钛合金(IKMI829,IMI834,Ti1100,BT18Y,BT36)、钛铝化合物为基的钛合金(Ti3Al(α2)和TiAl(γ))和阻燃钛合金(AlloyC,BTT-1和BTT-3)等4个方面,对航空航天用新型钛合金的新进展作了简略介绍。  相似文献
2.
提高高温钛合金性能的途径   总被引:20,自引:6,他引:14  
介绍了高温钛合金的发展与现状,着重分析了美国、英国、俄罗斯高温钛合金的发展和现状,探讨了高温钛合金的发展方向,并针对高温钛合金研究和设计中存在的困难,初步提出了一些解决问题的途径,即寻找新的添加元素,发掘与应用稀土元素,开发以Ti3Al和TiAl化合物为基的抗蠕变合金、研究抗氧化涂层等。  相似文献
3.
原位反应法制备Al/Al3Ti复合材料组织和性能   总被引:9,自引:0,他引:9       下载免费PDF全文
本研究采用一种新型的原位反应工艺,使TiO2粉剂与纯铝熔体反应,生成Al3Ti颗粒,然后采用搅拌铸造法制备Al/Al3Ti复合材料。生成的Al3Ti颗粒尺寸细小,为2~3μm,而且分布均匀,与基体结合好。当TiO2加入量为纯铝基体的30wt%、反应温度为920℃时,复合材料的抗拉强度比纯铝基体提高71.5%,硬度提高134%,而延伸率较纯铝稍有下降。  相似文献
4.
γ—TiAl增压涡轮熔模铸造过程数值模拟研究   总被引:9,自引:0,他引:9  
根据熔模型壳离心浇注的铸造工艺特点,建立了γ-TiAl增压涡轮凝固传热过程的数值模型,推导了离心压力下γ-TiAl金属间化合物的凝固收缩和补缩过程数学模型,模拟计算了γ-TiAl增压涡轮铸件的温度场和收缩缺陷,结果表明,模型能可靠计算γ-TiAl增压涡轮铸件凝固过程的温度分布和准确预测铸件的收缩缺陷,数值模拟结果与实验结果吻合良好,数值模拟结果证实了前期工作所提出的进一步减少及消除收缩缺陷的优化工艺措施的合理性。  相似文献
5.
Microstructural control and mechanical properties of dual-phase TiAl alloys   总被引:8,自引:0,他引:8  
This paper summarizes our recent work on the effects of microstructural features on the mechanical properties of TiAl alloys prepared by powder and ingot metallurgy. TiAl alloys based on Ti-47Al-2Cr-2Nb (at%) were alloyed with small amounts of Ta, W, and B additions for control of alloy phases and microstructure. The alloys were processed by hot extrusion above and below T, followed by short- and long-term heat treatments at temperatures to 1350 °C in vacuum. The microstructural features in the lamellar structures were characterized by metallography, SEM and TEM, and the mechanical properties were determined by tensile tests at temperatures to 1000 °C. The tensile elongation at room temperature is mainly controlled by the colony size, showing an increase in ductility with decreasing colony size. The yield strength, on the other hand, is sensitive to the interlamellar spacing. Hall-Petch relationships hold well for both yield strength and tensile elongation at room and elevated temperatures. TiAl alloys with refined colony size and ultrafine lamellar structures possess excellent mechanical properties for structural applications at elevated temperatures.  相似文献
6.
The current understanding of the metallurgy of the orthorhombic alloys in the Ti---Al---Nb system is reviewed with emphasis on tensile and creep properties of ternary alloys. It is shown that increasing the Nb content of alloys from 15 to 27 at% at a constant Al level significantly increases both the tensile and creep properties of equiaxed as well as lath structures, while small changes in Al content have a large effect on creep. For a given alloy composition, the amount of B2(β) phase and its distribution and the scale of O laths influences tensile properties, while creep properties depend on the volume fraction of equiaxed 2/O phase present in the structure as well as the size of O laths.  相似文献
7.
微量硼和应变速率对变形TiAl合金室温力学性能的影响   总被引:5,自引:0,他引:5  
以形变Ti47Al2Mn2Nb合金为对象,研究了微量硼合金化和应变速率对TiAl合金室温力学性能的影响。发现添加微量(1.0%,摩尔分数)硼就能有效地细化形变Ti47Al2Mn2Nb合金的近全片层组织,显著提高其室温强度,并在一定程度上改善室温塑性;变形TiAl合金不论添硼与否,其室温强度均随应变速率的升高而升高,而延伸率对应变速率不太敏感;微量硼合金化和应变速率对变形TiAl合金室温断裂方式无明显影响。  相似文献
8.
Strength and ductility in TiAl alloys   总被引:5,自引:0,他引:5  
Young-Won Kim 《Intermetallics》1998,6(7-8):623-628
Tensile behavior of two-phase TiAl alloys at room temperature (RT) is analyzed for duplex and lamellar microstructural forms. The Hall-Petch relationship with high constants in fully-lamellar material is explained as a combined function of grain-size and deformation-anisotropy. The low ductility and its inverse relationship with grain size are explained using the anisotropic tensile properties of lamellar structures and assuming that the fracture is controlled by the crack nucleation process involving the pile-ups of dislocations under shear stress. The crack initiation toughness and associated strains near the crack tip are used to explain the inverse relationship between ductility and toughness.  相似文献
9.
γ—TiAl增压涡轮近净形铸造过程实验研究   总被引:5,自引:0,他引:5  
γ-TiAl金属间化合物的成形工艺是材料成形领域的前沿领域和研究热点,本研究采用水冷铜坩埚真空感应凝壳技术和熔模型壳离心浇注的铸造方法制备γ-TiAl增压涡轮,通过改善冒口工艺获得了健全的γ-TiAl涡轮铸件,分析了γ-TiAl增压涡轮的凝固过程和收缩缺陷产生原因,结果表明,增大冒口与然件的模数之差以及冒口与铸件的体积之比有利于减少及消除涡轮铸件的收缩缺陷,为给数值模拟研究提供热物性参数,针对涡轮铸件用钛铝合金,实验测试了合金的热膨胀系数,比热和热导率等物性参数,其与温度的关系分别为:α1=8.10651 0.0073T-2.97619E-6T^2,Cp=668.28158-0.013T 1.11905E-4T^2;λ=19.82252-0.02781T 6.5197E-5T^2-3.21096E-8T^3.  相似文献
10.
Gas atomized Ti48Al2Mn2Nb powders were used as a feedstock material for direct laser fabrication (DLF) of near net shape samples. The microstructures of these laser treated samples were characterized using optical, scanning (SEM) and transmission electron microscopy (TEM), both immediately after laser fabrication and after heat treatments. These characterizations have shown that the microstructure is extremely fine but inhomogeneous in comparison to the conventionally processed material. The process parameters such as laser power and scanning speed controlled the microstructural morphology. The laser-treated microstructure remained stable up to 973 K, but rapid grain coarsening occurred at 1273 K. A fully recrystallized, uniform microstructure was obtained after annealing at 1073 K for 24 h, with an apparent compositional homogeneity. Annealing in the phase field followed by air cooling and annealing in (2+γ) phase region resulted in uniform microstructure. However, the microstructure was much coarser than the microstructure of the DLF samples.  相似文献
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号