共查询到20条相似文献,搜索用时 15 毫秒
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ZHANG Jingguo ZHANG Xiaomin LIN Yijian Shanghai Iron Steel Research Institute Shanghai ChinaKE Jun 《金属学报(英文版)》1989,2(5):383-386
The microstructure of a laser-melted Fe-4% C-10% Sn alloy has been studied.Anon-crystalline phase was found in the upper part of the laser-melted zone:At the bottom ofthe melted zone,however,the microcrystalline zone which consists of α-Fe and a bet phasewas observed.Fine twinning martensite exists in the other area of the melted zone. 相似文献
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快速凝固Al—TiC自生复合材料的显微组织和力学性能 总被引:3,自引:0,他引:3
将常规熔铸工艺与快速凝固技术相结合,成功地制备出Al-TiC自生复合材料.常规熔铸Al-TiC自生复合材料中TiC的体积分数为14.5%,颗粒尺寸为0.2-1.0μm,一般呈聚集态分布;与类似工艺条件下的人工复合材料相比,业已表现出较好的综合力学性能.快凝及热挤成型以后,TiC的体积分数约为13.5%,颗粒尺寸减至40-80nm,并弥散分布于晶粒尺寸为0.30-0.80μm的α-Al基体上,室温拉伸强度增加了约100MPa,表现出良好的高温力学性能. 相似文献
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DD8单晶镍基高温合金经激光扫描快速熔凝后, 熔池表面宽度随扫描速率增加变窄; 一次枝晶间距随冷却速率增加而减小. 分析表明: 熔凝后元素的枝晶偏析不明显, 合金成分趋于均匀. 熔凝后的凝固形态由熔池底部到表面依次为准平面凝固、胞状凝固、胞枝状凝固和细密枝晶凝固. 准平面和胞状凝固区由γ固溶体及弥散γ'相 (20 nm) 组成. 在胞枝晶和枝晶凝固区, 枝晶间出现一种高Ti含量条状相. 在过渡区, γ固溶体及γ'相皆部分熔凝, 未全溶的γ'相成为熔凝再析出弥散γ'相的核心, 过渡区γ'相呈堆状分布. 相似文献
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快速凝固Al-TiC自生复合材料的显微组织和力学性能 总被引:3,自引:0,他引:3
将常规熔铸工艺与快速凝固技术相结合,成功地制备出Al-TiC自生复合材料.常规熔铸Al-TiC自生复合材料中TiC的体积分数为14.5%,颗粒尺寸为0.2-1.0μm,一般呈聚集态分布;与类似工艺条件下的人工复合材料相比,业已表现出较好的综合力学性能.快凝及热挤成型以后,TiC的体积分数约为13.5%,颗粒尺寸减至40-80nm,并弥散分布于晶粒尺寸为0.30-0.80μm的α-Al基体上,室温拉伸强度增加了约100MPa,表现出良好的高温力学性能. 相似文献
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快凝Al-Fe-M-Si合金的显微结构对熔体热历史的敏感性 总被引:3,自引:0,他引:3
研究了不同成分的快凝Al-Fe-M-Si(M=Ti,Nb,Cr+Mo,W)合金显微结构对熔体热历史的敏感性.结果表明:在相同熔体热历史条件下,不同成分的快凝Al-Fe-M-Si合金的显微结构有着明显差别;在1323K,5min至1523K,5min的熔体热历史制度范围内,只有快凝Al-Fe-W-Si合金显微结构对熔体热历史比较敏感.作者认为合金过热熔体的微观不均匀区的大小是影响快凝Al-Fe-M-Si合金显微结构对熔体热历史的敏感性的主要因素. 相似文献
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CAO Mingzhou HAN Dong ZHANG Tao LI Dong Institute of Metal Research Academia Sinica Shenyang China Associate Professor Institute of Metal Research Academia Sinica Shenyang China 《金属学报(英文版)》1993,6(2):117-120
The rapidly solidified powder of Ti-34Al-2Mn alloy was obtained by means of ultrasonicgas atomisation (USGA) technique.The tupical size of the powder is 27 μm.X-ray diffractionresults show that the powder consists of major α_2-phase and minor γ-phase.Under opticalmicroscope both equiaxed and dendritical microstructure features were observed on RS pow-der sections.After annealing at 900 ℃/for 2 h in vacuum,most of α_2-phase transforms intoγ-phase,resulting in refinement of structure. 相似文献
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利用脉冲激光辐照研究超高温度梯度下表层预置ZrO2纳米颗粒涂层的 18-8奥氏体不锈钢的快凝组织形态、微结构特征及力学性质,结果表明,在表层约15μm范围内形成Zr的合金化微区, Zr最大含量(原子分数)为43.3%,但Zr成分分布存在不连续特征;预置纳米 ZrO2陶瓷涂层明显提高了激光作用深度.超高温度梯度和高冷却速率显著细化了快凝亚组织并得到超细枝晶及胞晶,并观察到位错胞及栅栏李晶两类亚晶,而激光熔区的外延生长机制未使晶粒细化.激光辐照后,合金化区硬度增加而弹性模量降低,其余部分硬度增加而弹性模量无变化. 相似文献
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MANG Weishi WANG Guozhi ZHANG Yongchang HU Zhuangqi SHI Changxu Institute of Metal Research Academia Sinica Shenyang China Yongchang Associate Professor Institute of Metal Research Academia Sinica Shenyang China 《金属学报(英文版)》1990,3(4):236-242
A rapidly solidified microcrystalline Al-Li-Cu-Mg-Zr alloy and its superplasicity have beeninvestigated.An optimum tensile elongation of 585% was obtained at 540℃ and strain rate1.67×10~(-2)s~(-1).The superplastic Al-Li alloy is manufaetured using thermomechanical pro-cessing:solution,overaging,warm rolling and recrystallization.Microstructural changes inthermomechanical processing and cavitation occurred during superplastic deformation havebeen observed.The superplastic failure of alloy may be caused mainly by nucleation andgrowth of cavities as well as the linkage around grains. 相似文献
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NING Yuantao ZHO U Xinming LI Yongnian Kunming Institute of Precious Metals Kunming China 《金属学报(英文版)》1991,4(8):143-146
The 0,05—0.08 mm thick splat foils of Ag-Tb alloy,containing Tb up to 10 at.-%,were made by the hammer-anvil technique.The cooling rate was in order of 10~6 K/s.The metastable extension of solid solubility of Tb in the alloy was measured to be up to 5 at.-% by lattice parameter method.The secondary phase in metastable eutectic structure was identi- fied as Ag_3Tb from diffraction pattern.The microstructure and micro-defect in as-quenched Ag-Tb splat foil were also observed. 相似文献
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SHAO Guosheng SHEN Ningfu Zhengzhou Institute of Technology Zhengzhou China 《金属学报(英文版)》1992,5(4):292-296
An addition of Ti as alloying element to Al-Si binary alloy will reduce the undercooling-abili-ty on rapid solidification of the melt-spun ribbon.The microstructure will be encoarsenedeven at initiation of its solidification,so as to aggravate the eellular segregation of Si in thealloy ribbon. 相似文献
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MICROSTRUCTUREANDMECHANICALPROPERTIESOFRAPIDLYSOLIDIFIEDAl-FeBASEDALLOYSW.J.Park;S.Ahn;R.Schmees;andNackJ.Kim(1)(CenterforAdv... 相似文献
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铬含量及时效对快速凝固Cu-Cr-0.05Zr合金组织与性能的影响 总被引:2,自引:0,他引:2
研究了铬含量及时效对快速凝固Cu-Cr-0.05zr合金组织与性能的影响。结果表明,该合金系的硬度随过饱和的铬含量增加而线性提高;临界凝固速度随铬含量的增加而增大;铬的析出会降低它在铜中的极限溶解度;当凝固速度高至使柱状晶间距小于1μm时,铬在单相过饱和固溶体中的极限溶解度可超过3%。合金Cu-0.84Cr-0.05Zr经时效处理后,硬度提高一倍以上。铬改善了此类合金的热稳定性及硬化效应。 相似文献