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31.
H. Mughrabi H. Biermann T. Ungar 《Journal of Materials Engineering and Performance》1993,2(4):557-564
The γ-γ lattice mismatch of specimens of the monocrystalline nickel-base superalloy SRR 99 has been measured by a high-resolution
X-ray diffraction technique for the undeformed state and after high-tem-perature creep deformation. During creep deformation
beyond the minimum creep rate (total strain =0.5%), the lattice mismatches, measured in and perpendicular to the [001] stress
axis, respectively, un-dergo changes in opposite directions. This reflects the buildup of a complex deformation-induced triaxial
state of internal stress in the phases y and γ. The overall resolved shear stresses that act in γ and y due to the combined
action of the external and internal stresses are estimated, and the conditions under which cutting of the γ phase by dislocations
should occur are discussed. 相似文献
32.
Jung-Chel Chang Cheol Choi Jae-Chul Kim Young-Hoon Yun 《Journal of Materials Engineering and Performance》2003,12(4):420-425
Effects of the hot-isostatic pressing (HIP) process on microstructures and mechanical properties of Ni-base single crystal
superalloy CMSX-4 were investigated. In the overall heat treatment process, the HIP treatment remarkably induced the healing
behavior of micropores and decreased the pore size and porosity of superalloy CMSX-4 compared with normally treated specimens.
The microstructure of γ′ phase after the HIP process showed rather a coarsening tendency and could be developed by the partially solution and aging
treatment. Consequently, the elimination of cast micropores using the HIP step resulted in the inhibition of crack initiation
in microstructure and improved the stress-rupture lives of Ni-base single crystal superalloy by 185%. 相似文献
33.
根据已知镍基合金成分和γ′相成分,运用分层宽容多目标优化法,分别计算了γ相成分及γ′相含量.优化测算过程的实现是通过建立使杠杆定律等式两端数值差最小和两相共格错配度最小的目标函数,并通过设置γ′相含量和基体相成分取值范围的约束条件而实现的.验证了该方法的可行性和准确性. 相似文献
34.
IntroductionSLlperalloyandheat-resistingsteelarenowwidelyusedasstructurematerialsinaerospace,a\-lationalldshipbuildingindustries.Nickel-basesuperalloywasfirstlyrevealedasanengineeringmaterialduringtheearly1960swhenitwasrecognizedasbeingsuitableforllledium-temperaturegasturbinel'l.Now.nickel-basesuperalloyhasbeenpracticallyusedinhigheffectiveturbinestosatisfytheincreasingdemandsforhighertemperatureenvironmentsIZI.Insomeaerospaceengines,theimpellersshouldserveattemperatureof1000C~1100C,andala… 相似文献
35.
王世普 《沈阳黄金学院学报》2010,(2):116-120
研究了连轧生产线生产的GH4648合金热轧棒材的组织与性能.采用热连轧过程的自动化控制系统调整棒材的轧制速度、保持稳定的终轧温度,从而获得晶粒组织均匀、α-Cr相形态与分布合理的热轧棒材.与传统的横列式轧机相比,工艺更稳定、可控,热轧棒材的组织稳定、性能提高. 相似文献
36.
用2种硬质合金涂层刀具进行铁基高温合金GH2132的高速干铣削试验,采用电子扫描显微镜(scanning electron microscopy,SEM)观察刀具的磨损形貌,对刀具的主要磨损机理进行了分析.结果表明:刀具的磨损形态主要是后刀面磨损;KC725M涂层由TiN、TiAlN组成,涂层易剥落;KC525M涂层只有1层TiAlN,涂层不易脱落,但由于机械冲击产生沟槽磨损,形成应力集中,导致在切削刃处产生较大的磨损;不论KC525M还是KC725M,涂层剥落后,切削区产生的瞬时高温均使基体中粘结相发生软化,造成硬质相颗粒脱落和基体的剧烈磨损.研究结果可用于指导高速切削刀具材料的设计、合理选用及刀具磨损控制. 相似文献
37.
采用有限元软件对高温合金IN690管材挤压损伤进行预测,研究挤压速度对损伤的影响规律,得到不同的挤压条件下的挤压阈值。不同挤压速度下损伤的变化随着挤压速度变化呈现先增大后减小的趋势。模拟摩擦系数为0.01、0.05、0.1、0.2条件下的损伤,在摩擦系数为0.01时,坯料表面比较光滑,损伤比较轻;摩擦系数为0.2时,表面凹凸不平,损伤严重。 相似文献
38.
39.
The Main Degradation Modes of an Aluminide Coating on a Co-Base Superalloy During High-Temperature Oxidation in Air 总被引:1,自引:0,他引:1
Degradation of aluminide coatings occurs by two ways, one by coating oxidation, and the other by interdiffusion of Al. In this paper, the structure variation and phase transformation are analyzed for the aluminide coating on a newly developed Co-base superalloy (DZ40M alloy) after oxidation at 900 and 1000°C in air. The results show that degradation of this coating was mainly by oxidation at 900°C, but principally by interdiffusion at 1000°C. The main degradation mode of the coating is primarily dependent on the oxidation temperature and the specific structure of the coating itself. 相似文献
40.
The creep behavior of directionally solidified (DS) superalloy IC 10 was investigated under 192 MPa and 218 MPa at 980 ℃. Under the testing conditions, the marked creep characteristic of the superalloy is that the creep curve has a short primary and secondary stage and a long tertiary stage. Another creep characteristic is that the superalloy has excellent plasticity at high temperature. To study the creep behavior, the microstructure was observed by SEM and TEM. Different from other microstructure of Ni-base superalloys, superalloy IC10 forms incompletely rafted γ' phase during the creep processes. To understand the creep deformation mechanism of superalloy IC10, the movement of dislocations was analyzed. The results show that the dislocations moving in the γ matrix and climbing over the γ' precipitates is the main deformation mechanism under the experimental conditions. 相似文献