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目的 消除GH4169合金锻造混晶组织,获得高品质GH4169合金锻件的制备工艺.方法 对变形后锻件进行后续的热处理退火,探明均匀细化锻造混晶组织的热处理工艺方法与机制.首先,设计并实施不同的单级退火工艺及双级退火工艺.随后,统计不同热处理退火工艺下锻造混晶组织的平均晶粒尺寸.最后,分析不同热处理退火工艺下混晶组织的细化机制与不足.在此基础上,获得能均匀细化锻造混晶组织的热处理工艺方法.结果 采用低温时效处理和后续的高温再结晶退火处理结合的双级热处理退火工艺,可以有效地将锻造混晶组织均匀细化至ASTM 10级以上.结论 变形后进行热处理可以通过再结晶行为显著改善锻造混晶组织的均匀性与细化程度.高温再结晶退火热处理前预先析出足够数量的δ相,有利于更好地均匀细化变形混晶组织. 相似文献
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对Mg-Zn-Zr合金进行高应变速率多向锻造变形,研究了其组织演变和力学性能。结果表明,高应变速率多向锻造工艺能强烈细化合金的晶粒组织,形成由蜂窝状粗大再结晶组织和岛状细小再结晶组织构成的新颖组织,初始晶界附近和初始晶粒内部的再结晶机制分别是旋转动态再结晶和孪生诱发动态再结晶。由于高应变速率多向锻造工艺具有强烈的晶粒细化能力并能有效避免强烈的基面织构,可大幅提高合金的综合力学性能。累积应变∑Δε=2.64时,ZK21和ZK60抗拉强度、屈服强度和延伸率分别为341.6 MPa、270.7 MPa、25.1%和330.2 MPa、232.3 MPa、24.8%。 相似文献
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电沉积法制备Ni-Fe合金箔具有工艺简单,能耗低,产品规格不受限制等优点,但其塑性和弹性模量较低限制了其应用发展.为了改善电沉积Ni-Fe合金箔的力学性能并扩大其应用范围,本文通过高温热处理方法改善其力学性能,采用SEM,XRD,EBSD分析手段对电沉积Ni-Fe合金箔晶粒组织和结构进行了分析,通过高温热台显微镜进行原位在线观测晶粒组织的演变过程,并对热处理后的电沉积Ni-Fe合金箔进行力学性能分析.研究表明,热处理过程中电沉积Ni-Fe合金箔经历细晶组织阶段、混晶组织阶段和粗晶组织阶段,其中,在1 000~1 050℃容易发生晶粒异常长大.细晶组织阶段,电沉积Ni-Fe合金箔能够保证较高的强度,且塑性和弹性模量明显提高,综合性能较好;混晶组织阶段,强度和塑性较低,弹性模量有一定程度提高;粗晶组织阶段,强度很低,但塑性和弹性模量有较大程度提高. 相似文献
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《材料导报》2020,(14)
针对2219铝合金环件在传统高温变形工艺过程中存在的晶粒组织粗大问题,本研究提出一种环件深冷变形新工艺。借助金相显微镜(OM)、扫描电镜(SEM)、透射电镜(TEM)、拉伸测试等分析手段研究了深冷变形及传统高温变形工艺对2219铝合金环件晶粒组织与力学性能的影响。结果表明:深冷变形以高密度位错形式累积大量存储能,有助于在后续固溶及轧制过程中通过再结晶细化晶粒。晶粒的细化使得应力在合金内部的分布更均匀,裂纹扩展路径也更加曲折,沿晶断裂成为其主要断裂机制。相比480℃高温变形工艺,样品在液氮条件下进行深冷变形并结合热处理,可明显提升其综合力学性能,其抗拉强度、屈服强度、延伸率平均提高了20 MPa、22 MPa、3.0%,同时各向异性也明显降低。 相似文献
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目的 研究ZTC18合金双重退火热处理时合金微观组织和力学性能的变化规律。方法 通过对ZTC18合金熔模精密铸造拉伸试棒试验件进行双重退火热处理实验,对比不同热处理工艺铸件的微观组织和力学性能,分析其变化规律。结果 不同的双重退火温度下,晶粒尺寸无明显变化,随着第2级退火温度升高,晶粒内部初生α相由长针状逐渐变化为棒状及等轴颗粒,次生α相逐渐减少,合金的强度随第2级退火温度升高而降低,塑性则呈增加趋势。结论 通过双重热处理可以达到调整合金强度塑性比的目的,对比HIP后的室温拉伸数据,在二级退火温度为610和590 ℃的试样(空冷或炉冷)的强度和塑性综合匹配性较好,抗拉强度能够达到1100 MPa,伸长率大于11%。 相似文献
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研究了不同热处理工艺对TC4-DT钛合金棒材显微组织和力学性能的影响。结果表明:TC4-DT合金在两相区经过普通退火和再结晶退火后组织发生再结晶,α相尺寸有所增大,具有较好的塑性。经过两相区固溶+时效处理得到双态组织,通过控制固溶时冷却速度及时效温度来调整次生α片层厚度,使得合金强度和断裂韧性得到改善。经单相区固溶水冷得到马氏体组织,随时效温度提高,α片层厚度增加,但析出的次生α相含量减少,导致合金的强度和断裂韧性有所下降。而在单相区固溶空冷+高温时效处理,获得的α片层厚度进一步增大,有助于提高塑性和断裂韧性。采用950℃/1h/WQ+550℃/6h/AC两相区固溶+时效的热处理工艺,可实现合金强度、塑性、韧性的较好匹配,获得优良的综合性能。 相似文献
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本工作提出了7050铝合金自由锻件深冷变形新工艺,即在热处理前将合金置于液氮中,待合金降至液氮温度后进行单道次压缩变形。经热处理后,采用硬度仪、室温拉伸、电导率、晶间腐蚀、剥落腐蚀测试及金相显微镜、扫描电镜和透射电镜研究了不同深冷变形量对7050铝合金微观组织、力学性能和抗腐蚀性能的影响。结果表明:随着深冷变形量的增大,合金再结晶比例上升,晶粒逐渐细化,晶界析出相间距减小,由非连续分布转变为连续分布,晶界无析出带宽度变窄;合金的抗拉强度、屈服强度与硬度明显升高,最大提升幅度分别为33 MPa、35 MPa和10. 5HV,延伸率最大提升幅度为1. 5%;电导率呈现小幅下降趋势,合金抗晶间腐蚀和抗剥落腐蚀性能降低,30%深冷变形量对应的晶间腐蚀最大深度为167μm,剥落腐蚀等级为EC。 相似文献
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R. Wever 《Packaging Technology and Science》2011,24(4):211-222
In the literature, there are several authors arguing for the optimization of the packaging volume as an important factor in distribution efficiency. Within the context of packaging of durable goods, these authors present significant economic savings, usually illustrated by qualitative examples of redesigns. So far, these papers are limited to: (a) the economic aspect of volume (b) packaging for which the main functionality is distribution‐related, and (c) mostly qualitative empirical data. This current paper aims to contribute to this literature by: (a) arguing that volume is also a significant factor from an environmental perspective (b) including packaging for which the main functionality is marketing‐related, and (c) presenting quantitative data of over 1000 packed durable goods, covering consumer electronics, domestic appliances, toys, power tools and furniture. Several strategies for volume optimization are discussed in relation to different packaging functionalities. Copyright © 2011 John Wiley & Sons, Ltd. 相似文献
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船舶与集装箱用钢板预处理过程中所用磨料的对比 总被引:4,自引:0,他引:4
对船舶与集装箱用钢板涂装前预处理过程中,抛(喷)丸清理(除锈、刻蚀)用各种磨料的性质、磨料硬度与侵入性及耐久性(寿命)的关系、磨料的形状与清理效果的关系、磨料的粒度与覆盖率、冲击功的关系作了对比分析,提出了合理选用磨料的原则。 相似文献
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《Materials Science & Technology》2013,29(10):1163-1167
AbstractA computer model has been developed to predict the processing window (austempering window) for austempered ductile iron (ADI). The model is a modification of an existing model for the isothermal decomposition of austenite in bainitic steels. It was calibrated using experimental data from the literature. In order to validate the model, the processing window corresponding to a ductile iron of composition 3.41%C, 2.46%Si, 0.36%Mn, 0.18%Mo, and 0.25%Cu is predicted and compared to experimental data. Computer assisted image analysis was used to investigate the volume fraction of martensite at the lower boundary of the processing window. X-ray diffraction was used to calculate the normalised volume fraction of austenite at the upper boundary of the processing window. The results show that the model successfully predicts the processing window corresponding to the iron investigated in this study. 相似文献
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降低当前不断增长的资源消耗,这要求未来的产品循环在材料和能源方面更为有效。这将在保证技术先进的同时延长产品使用寿命和耐用性的基础上藉产品再生利用来实现。符合再生利用的产品必须具备开放式的系统结构,并且具有适合几个生命周期的动态的产品结构。为了此类产品的构造和设计,本文以机床为例,制订了支持设计的特殊规则和提示。在再生利用能力方面的设计质量可以用来有评价标准的清单予以检验。 相似文献
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Pillinger C 《Philosophical transactions. Series A, Mathematical, physical, and engineering sciences》2011,369(1936):607-619
This paper describes the chemical concepts used for the purpose of detecting life in extra-terrestrial situations. These methods, developed initially within the oil industry, have been used to determine when life began on Earth and for investigating the Moon and Mars via space missions. In the case of Mars, the Viking missions led to the realization that we had meteorites from Mars on Earth. The study of Martian meteorites in the laboratory provides tantalizing clues for life on Mars in both the ancient and recent past. Meteorite analyses led to the launch of the Beagle 2 spacecraft, which was designed to prove that life-detection results obtained on Earth were authentic and not confused by terrestrial contamination. Some suggestions are made for future work. 相似文献
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An optimum policy for the warrants for and the design of guardrails based on benefit maximizing criteria is presented. It is shown that the strength, the number of classes of standards, and the location of guardrails should be determined simultaneously with due consideration for the nation-wide distribution of roadside dangers and the impact of colliding vehicles. Dynamic programming is used for optimization. 相似文献
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A. A. Bolonin 《Measurement Techniques》2007,50(5):503-508
An interference comparator is described for measuring line scales and gratings in which total conformity is provided for the
sections being compared, the effect of water vapor in the refractometer chamber is overcome, and a laser confocal microscope
and digital processing of signals are used. In comparisons, the length-dependent divergence is 1·10−8L, and independent of length the standard divergence is 2 nm.
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Translated from Izmeritel’naya Tekhnika, No. 5, pp. 31–35, May, 2007. 相似文献