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排序方式: 共有252条查询结果,搜索用时 15 毫秒
61.
1. IntroductionBabbitt alloy, copper-lead alloy, aluminum-tin alloyand aluminum-lead alloy are well known bush materials[1-6].As the progress in automobile industry, there arises a bigdemand of high speed and long life bush materials. A newbush material AlSn8Pb2Si2.5Cu0.8Cr0.2 (ASP) was developedto satisfy the demand in America [7]. This material hasmany advantages, such as good antifriction behavior, highstrength, high wear resistance, good friction consistencyand high load-bearing abilit… 相似文献
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《Baosteel Technical Research》2015,9(4):11-15
The effect of austenite deformation on the pearlite microstructure of eutectoid steel w as investigated by hot uniaxial compression tests using a Gleeble 1500 thermo-mechanical simulator. The results show ed that the deformation of the austenite phase accelerated the transformation of pearlite,leading to a smaller colony size and a smaller interlamellar space of pearlite; meanw hile,the orientation of pearlite lamellae became more heterogeneous,and the lamellar thickness decreased. Larger strain of austenite w as observed to accelerate the spheroidization process of carbides w ithin pearlite colonies. 相似文献
64.
《稀有金属材料与工程》2018,35(5):20-23
为研究具有原始粗片层组织的Ti5321合金热压缩变形过程中流变应力、显微组织等随变形条件的变化,在Gleeble-2800型热模拟试验机上进行高温热压缩试验,试验温度790~850 ℃,应变速率为0.01~1 s-1,变形量为30%~70%。结果表明:Ti5321合金的软化机制与片层组织球化和动态再结晶有关,变形量和变形温度是影响合金片层组织球化及β再结晶的主要因素。同一变形温度和应变速率下,随着变形量的增大.会出现片层α相球化及β相再结晶现象。当应变速率和变形量相同时,低温变形主要发生的是片层α相球化行为,高温变形发生的是β相的再结晶。 相似文献
65.
以稀土镁球墨铸铁为研究对象,用扫描电镜观察了其中的夹杂物,并进行元素面扫描分析,结合热力学计算结果和动力学条件,分析了Ti-Ce-S复合夹杂物的形成过程.结果表明,Ti-Ce-S复合夹杂物呈块状,分布在珠光体和铁素体的晶界处,尺寸为3 μm;球化处理过程中,CeS为TiS的形成提供非均匀形核核心,Ce对TiS的还原作用是促进Ti-Ce-S复合夹杂物形成的主要因素,Ti-Ce还与镧、钡、镁等元素复合形成夹杂物,分别是Ti-Ce-La-S、Ti-Ce-Ba-S、Ti-Ce-Ba-Si-S、Ti-Ce-V-C和Ti-Ce-La-Mg-C-N-S复合夹杂物.钛、铈等元素间的充分反应和此类夹杂物的有效去除是保证球化效果的重要因素. 相似文献
66.
Effect of repetitive equal channel angular pressing on microstructural stability of low carbon steel
Young Kuk Kim Sang Min Kim Ki Seung Lee Jong Jin Pak Dong Hyuk Shin 《Metals and Materials International》2001,7(5):437-442
The microstructure of ultrafine grained low carbon steel processed with repetitive equal channel angular pressing was investigated.
A submicron ferrite grain size of ∼0.2 μm was achieved by pressings of up to 12 passes. Microstructural examination by TEM
with SAD pattern on the pressed samples revealed the presence of high density dislocations inside the ferrite grains and ill-defined
grain boundaries. These features became more significant as the number of pressings increased. The static annealing of the
pressed samples at 753 K up to 24 hrs resulted in a recovery which was associated with the absorption of the dislocations
by the grain boundaries. However, the recovery was inhibited as the number of pressings increased. The annealing process also
led to the precipitation of cementite particles in ferrite colonies. The presence of precipitated particles inside the ferrite
grains enhanced the microstructural stability of the low carbon steel at elevated temperatures. 相似文献
67.
Study on the flow properties of Ti-6Al-4V powders prepared by radio-frequency plasma spheroidization
Wen-Hou Wei Lin-Zhi Wang Tian Chen Xuan-Ming Duan Wei Li 《Advanced Powder Technology》2017,28(9):2431-2437
Spherical Ti-6Al-4V powders were prepared using radio-frequency plasma spheroidization. A laser particle size analyser, a scanning electron microscope, an X-ray diffractometer and a Freeman FT4 powder rheometer were used to analyse the granulometric parameters, micro-morphologies, phase constitutions and flow properties of the raw and the spheroidized powders, respectively. The spheroidized powders exhibited an almost 100% degree of sphericity, smooth surfaces, favourable dispersion and narrow particle size distribution under appropriate plasma technological parameters. The average particle size of the spheroidized powders increased slightly as compared with that of the raw powders. In addition, the spheroidized powders exhibited higher conditioned bulk density and improved flow properties (including the dynamic flow properties, aeration, compressibility, permeability and shear properties) as compared with those of the raw powders. 相似文献
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含钨白口铸铁共晶碳化物团球化研究 总被引:1,自引:0,他引:1
研究了Ce、K、Na复合变质处理对含钨白口铸铁组织和性能的影响,提出了评价碳化物变质效果的圆度概念,并讨论了共晶碳化物团球化对力学性能和耐磨性能的影响。变质处理后,由于共晶碳化物形态的改善,含钨白口铸铁的力学性能,尤其是冲击韧性大幅度提高,抗冲击磨损性能也显著提高。经变质处理的含钨白口铸铁轧辊使用寿命比高铬铸铁轧辊提高20%以上,生产成本降低30%以上。 相似文献
70.