共查询到17条相似文献,搜索用时 62 毫秒
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Ti—Al系金属间化合物的价电子结构与其力学性能的关系 总被引:3,自引:0,他引:3
根据余氏理论提出了价电子结构均匀分布因子α,建立了价电子结构与力学性能的关系,分析了Ti-Al系金属间化合物的价电子结构,并由所给出的经验公式计算了其力学性能,所得结果与实验数据进行了比较。 相似文献
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采用不同加热加载方法对机械合金化Al3Ti/Al合金的使用环境进行了模拟试验研究,考察了该合金显微组织高温稳定性。结果表明,机械合金显微组织高温稳定性。结果表明,机械合金化Al3Ti/Al合金具有细小的晶粒组织(约为0.5μm),经过各种高温变形后合金组织并未粗化,具有很好的高温稳定性。该合金在350℃下的压缩屈服强度仍能保持在247MPa。 相似文献
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根据固体与分子经验电子理论的BLD方法,建立了40、40Cr、40CrMo钢马氏体价电子结构,利用C-Mc偏聚结构单元的nA值及共价键格上的电子对分布,研究了马氏体价电子结构对回火转变及力学性能的影响。 相似文献
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采用分子动力学方法模拟研究了不同冷速条件下液态Ti3Al合金的凝固过程。采用对相关函数法、原子团类型指数法(CTIM)对凝固过程中团簇结构的变化进行了分析。结果表明:在以1×1012K/s,1×1013K/s,1×1014K/s三种不同冷速条件下,系统都形成了以(12 0 12 0)基本原子团为主的非晶态结构,冷速对于Ti3Al合金凝固过程微观结构的影响主要是通过(12 0 12 0)基本原子团数目变化体现出来,(12 0 12 0)基本原子团在Ti3Al合金快速凝固过程团簇结构演变中起了主要作用。冷速越低,Ti3Al合金的玻璃态转化温度越低,体统形成的(12 0 12 0)基本原子团数目越多,非晶体的结构越稳定。 相似文献
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过共晶铝硅合金组织对切削加工性能的影响 总被引:5,自引:0,他引:5
为分析过共晶铝硅合金组织对其切削加工性能的影响,对两种化学成分相同但是组织结构不同的过共晶铝硅合金进行了切削试验研究并探讨了其切削机理。试验结果表明:过共晶铝硅合金经变质处理后组织中初晶硅的大小、形状和分布状况对切削刀具寿命和合金的切削加工表面质量影响极大,具有细小、分散而形状圆钝化初晶硅的合金有比较好的切削性能。造成这种影响的主要原因在于细小的硅粒比较容易协同基体塑性变形和被刀具压入切屑和已加工表面,而粗大的硅块往往发生解理破碎、脱落和位移,直接与刀具发生强烈摩擦并使已加工表面存留许多缺陷。 相似文献
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This article aims to study the friction and wear behavior of Ti3Al2.5V alloy sliding against EN-31 steel under dry condition using a multi-tribotester. The effect of variation in load and sliding velocity on wear rate, average coefficient of friction, and contact temperature has been studied and analysis of wear debris has been carried out. Scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS) were employed to study the morphology of the wear tracks and deduce microchemical information at the elemental level of worn samples, respectively. Results reveal that the wear rate of Ti-3Al-2.5V increases with increasing sliding velocity and increasing normal load with few exceptions. The average coefficient of friction decreases as the normal load increases with exceptions at some loads. SEM micrographs of worn samples obtained at different loads and sliding velocities show the formation of wear tracks on the surface due to ploughing and flaking of the matrix. The main mechanism responsible for wear of Ti3Al2.5V alloy sample is rupture of the matrix and abrasion. Wear debris analysis shows irregular-shaped wear particles with very sharp edges that appeared to be plastically deformed at high sliding velocity, whereas the wear debris is very loose and fine at lowest sliding velocity. 相似文献
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Titanium alloys, by virtue of their outstanding combination of properties, continue to evolve as direct replacements for steels in offshore production systems to meet the challenging offshore application conditions. However, the wider use of titanium and its alloys is frequently retarded by their reputation for poor tribological behaviour. It is because of this simple engineering scenario that comparative tribological behaviour of surface engineered Ti6Al4VELI in abrasive slurry has been evaluated to identify treatments capable of improving its wear behaviour. To best simulate potential application conditions, sliding wear tests were carried out using a block-on-wheel test configuration in abrasive mud slurry. The wear volumes lost from the surface engineered Ti6Al4VELI test blocks ranged from negligibly small for substrates plasma sprayed with either WC–Co, Ni–Cr or Mo, to approximately twice that measured for a steel test block in the cases of untreated, shot peened, electroless Ni plated and anodised Ti6Al4VELI. Hard chrome plated material and thermochemically treated material demonstrated a certain degree of wear, which however, was significantly less than that found for the steel block. 相似文献
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一种由连续SiC陶瓷纤维强化(CCFR)的新型金属间化合物基层状(MIL)复合材料Ti-(SiCf/Al3Ti)研制成功,其作为装甲防护材料在被侵彻过程中的微观变形机制、强化及失效机理有待研究。首先采用电镜扫描法(SEM)表征该材料的微观结构和界面特征,而后提出一种新的建模方法,基于高效的等效夹杂数值算法(NEIM),对刚性球侵彻靶体复合材料的早期接触过程进行建模,研究准静态加载下Ti-(SiCf/Al3Ti)复合材料的小变形弹塑性接触力学行为,并通过压痕试验验证该模型的精确性。结果表明,在球-面加载模式下,SiC纤维对CCFR-MIL复合材料的强度提高显著,而对延展性的强化却不如面-面加载模式下明显。此外,球-面加载模式下的最大塑性应变集中(MPSC)区出现在Al3Ti层最接近中心SiC纤维上边界的位置,并随载荷的增大沿深度方向延伸,该区域是裂纹萌生并扩展的高发区。当相邻SiC纤维的中心距为四倍纤维直径,且Ti层体积分数为40%时,CCFR-MIL复合材料的综合力学性能最佳。更高效数值方法的运用,节约了计算成本,清晰透彻地揭示了新型CCFR-MIL复合材料在被侵彻过程中的微观变形机制、强化及失效机理,并使参数化研究更为全面,便于材料的微观结构优化。 相似文献