• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Materials Science and Engineering >Microstructure formation and elevated temperature mechanical properties of directionally solidified Ti44A16Nb1Cr alloy
【24h】

Microstructure formation and elevated temperature mechanical properties of directionally solidified Ti44A16Nb1Cr alloy

机译：定向凝固Ti44a16NB1CR合金的微观结构形成及升高的温度力学性能

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

To improve room and elevated temperature mechanical properties of high-Nb TiAl alloys, Ti44A16Nb1Cr alloy has been prepared by cold crucible directional solidification (CCDS) technique under loaded power of 40 kW and pulling rate of 8.3 um/s. Macro/micro-structure and phase composition have been characterized. Tensile properties have been tested at room and elevated temperature and the related mechanisms have been revealed. Results show that equiaxed grains change to columnar grains growing up along the axial direction of ingot after CCDS. Phase component is still composed of α_2, y and B2 phases. Microstructure consists of lamellar clusters and network structure. The lamellar clusters in a grain possess the same orientation. The content and size of B2 phases decrease and some casting defects with small size decrease as well due to sufficient diffusion of Nb and Cr atoms under action of electromagnetic force during CCDS. Tensile results indicate that comprehensive mechanical properties of Ti44A16Nb1Cr alloy are improved significantly after CCDS. At room temperature, ultimate tensile strength and total strain are 523 MPa and 3.03%, respectively, which are improved by 18.1% and 64.7% compared with that of as-cast Ti44A16NblCr alloy (443 MPa and 1.84%). Moreover, fracture morphology also indicates that there are many deep ravines between cleavage steps and some similar dimples microstructure on cleavage steps. They are beneficial to improving comprehensive mechanical properties. At 973 K, ultimate tensile strength of Ti44A16NblCr alloy does not decrease at all, still reaching 530 MPa after CCDS. When service temperature rises to 1173 K, the strain is less than 4.28% showing excellent mechanical stability under tensile stress less than 436 MPa. The excellent stability for mechanical properties is due to thin lamellar phases, directional microstructure and large plastic deformation region.
机译：为了改善高Nb Tial合金的室温和高温力学性能，Ti44a16nb1cr合金已通过冷坩埚定向凝固（CCD）技术在负载功率为40kW和8.3μm/ s的拉伸率下制备。已经表征了宏/微结构和相位组成。在室内测试了拉伸性能，并且升高了温度，并且已经揭示了相关机制。结果表明，在CCD之后，Equiaxed谷物将沿着铸锭轴向成长的柱状颗粒。相组分仍由α_2，y和b2阶段组成。微观结构由层状簇和网络结构组成。谷物中的层状簇具有相同的取向。由于Nb和Cr原子的充分扩散在CCD期间，B2阶段的含量和尺寸减小，并且由于Nb和Cr原子的动作而降低了小尺寸的铸造缺陷。拉伸结果表明，在CCD后，Ti44a16nb1cr合金的综合力学性能显着提高。在室温下，最终拉伸强度和总菌株分别为523MPa和3.03％，与AS铸造Ti44a16nblcr合金（443MPa和1.84％）相比，增长18.1％和64.7％。此外，骨折形态也表明切割步骤之间存在许多深沟壑，并且裂解步骤的一些类似的凹坑微观结构。它们有利于改善综合机械性能。在973 k k，Ti44a16nblcr合金的最终拉伸强度根本不会降低，CCD后仍然达到530MPa。当服务温度上升至1173 k时，菌株小于4.28％，表示在小于436MPa的拉伸应力下的优异机械稳定性。机械性能的优异稳定性是由于薄的层状相，定向微结构和大塑性变形区域。

著录项

  • 来源
    《Materials Science and Engineering》 |2020年第21期|140038.1-140038.9|共9页
  • 作者

    Yangli Liu; Xiang Xue; Yingmei Tan; Hongze Fang; Hongzhi Cui; Ruirun Chen;

  • 作者单位

    National Key Laboratory for Precision Hot Processing of Metals Harbin Institute of Technology Harbin 150001 PR China;

    National Key Laboratory for Precision Hot Processing of Metals Harbin Institute of Technology Harbin 150001 PR China;

    National Key Laboratory for Precision Hot Processing of Metals Harbin Institute of Technology Harbin 150001 PR China;

    National Key Laboratory for Precision Hot Processing of Metals Harbin Institute of Technology Harbin 150001 PR China;

    School of Materials Science and Engineering Shandong University of Science and Technology Qingdao 266590 PR China;

    National Key Laboratory for Precision Hot Processing of Metals Harbin Institute of Technology Harbin 150001 PR China School of Materials Science and Engineering Shandong University of Science and Technology Qingdao 266590 PR China;

  • 收录信息
  • 原文格式 PDF
  • 正文语种 eng
  • 中图分类
  • 关键词

    TiAl alloy; CCDS; Columnar grains; Mechanical properties;

    机译：Tial合金;CCD;柱状颗粒;机械性能;

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号