共查询到20条相似文献,搜索用时 140 毫秒
1.
泡沫金属的研究与发展 总被引:26,自引:0,他引:26
泡沫金属是一咎新型的多孔功能材料,具有独特的结构和性能,其应用范围日益扩大。本文介绍了泡沫金属的研究现状,讨论了泡沫金属的发展方向。 相似文献
2.
3.
金属功能材料在航天航空工业方面的应用 总被引:7,自引:0,他引:7
概述了金属功能材料在当代航天航空工业方面的应用背景和应用范围,简介了金属功能材料在我国航天航空工业方面的应用情况,分析了未来的应用前景。 相似文献
4.
自从六十年代至七十年代初弄清了具有非晶态结构的金属及合金的特征,并开发了生产技术而使其能在商业上应用以来,在物理学和材料学的领域引起了人们的震动和关注,打破了固有的传统的对金属定义的认识。由于人们开拓了快速凝固的先进工艺技术,才能使非晶态合金能够出现并开拓出光辉的充满魅力的开发应用前景。 相似文献
5.
6.
7.
对石墨、类金刚石等传统碳材料在金属防腐蚀方面的应用进行了简要介绍,重点介绍了碳纳米管、石墨烯等新型碳材料在金属防腐蚀方面的研究及应用现状,并总结了它们的防腐机理。 相似文献
8.
10.
11.
12.
13.
Pan DongZhao YuguangXu XiaofengWang YitongJiang WenqiangJu Hong 《金属学报》2018,(9):1245-1252
42CrMo steel was widely used in many industry fields for its excellent hardenability and high temperature strength. Many transmission mechanisms and fasteners, such as roller and heat-resistant gear, are made of this steel. However, the ductility of 42CrMo steel is relatively low after quenching and tempering. During high tempering Mo riched carbides at grain boundary and undecomposable martensite at low tempering are the main reasons for poor ductility of 42CrMo steel. Grain refinement can enhance both strength and ductility significantly, but traditional refinement technology will cause intergranular oxidation so that strengthening effect was weak. Although thermomechanical treatment can achieve dynamic recrystallization, its refinement effect is unstable. Elecropulsing treatment, which makes significant change in microstructure and properties of metals, has been applied in many fields such as, modification of solidified microstructure of liquid metal, healing of fatigue crack, nanocrystallization of amorphous materials and so on. Moreover, this process can produce superior mechanical properties in metals. In order to improve the mechanical properties of 42CrMo steel better, high-energy and instantaneous electropulsing treatment was applied. In this contribution, 42CrMo steel was subjected to traditional and electropulsing treatment individually. It was found that EPQ treatment (480 ms electropulsing treatment, water cooled) results in finer grain, promoting the formation of retained austenite and twin martensite; EPT treatment (180 ms electropulsing treatment, air cooled) can stabilize retained austenite in EPQ specimen and induce multiphase structure. Mechanical properties results indicate that strength-ductility balance of EPQ and EPQ+EPT specimen are 32% and 13.9% higher than that of TQ (traditional quenched) and EPQ+TT (traditional tempered) specimen respectively. 相似文献
14.
15.
The effect of a pulsed electric current on the residual stress evolution of metal materials has been investigated.It was found that the surface and internal residual stresses in the as-quenched samples were reduced dramatically by electropulsing.A large number of experimental data show that the residual stress reduction is proportional to the initial residual stress and related to the material properties and electropulsing parameters.Under the combined actions of drift electrons,Joule heating,and residual stress,the dislocation mobility was enhanced,resulting in plastic strain and the decrease in residual stress.Drift electrons played a unique role in the electropulsing treatment,acting as an additional force pushing dislocations forward.The dislocations ultimately accumulated at a grain boundary,forming a parallel arrangement.Finally,the phenomenological equation of the residual stress evolution under electropulsing was derived from the experimental data. 相似文献
16.
17.
以ZA12合金为实验材料,在合金的凝固过程中进行了脉冲电流处理,研究电脉冲时间对作用结果的影响。实验结果表明,就细化合金的凝固组织、改善力学性能而言,在合金凝固的整个过程都进行脉冲电流处理比仅在合金凝固的前半段进行处理的效果要好。结合ZA12合金的凝固特性和电流对金属熔体的作用机制进行分析。认为在合金凝固后半段施加的脉冲电流处理促进了枝晶之间液体的流动。增强了枝晶间液体的补缩能力,并且导致部分小的枝晶熔断。从而进一步抑制了枝晶的生长.得到更均匀细小的凝固组织。从而对合金力学性能的改善效果也更为显著。 相似文献
18.
通过先对Zr55Ni5Al10Cu30合金熔体施加脉冲电流处理,再利用非真空吸铸法制备出Zr55Ni5Al10Cu30块体非晶合金的方式,研究了电脉冲孕育处理对非晶热稳定性及退火晶化的影响。差分扫描量热(DSC)及X射线衍射(XRD)分析结果表明:经电脉冲孕育处理后Zr55Ni5Al10Cu30块体非晶合金的玻璃转变温度上升,晶化温度降低,过冷液相区变窄,同时玻璃转变激活能和晶化激活能有所减少。电脉冲孕育处理没有改变Zr55Ni5Al10Cu30块体非晶合金退火晶化相演变过程,但提高了非晶退火晶化率。电脉冲孕育处理对Zr55Ni5Al10Cu30块体非晶合金的晶化起到了促进作用。 相似文献
19.
采用电脉冲处理FH690钢焊接热影响区,利用显微观察和和力学性能试验,分析了电脉冲效应对热影响区韧性的影响。缺口冲击试验结果表明电脉冲处理后热影响区的韧性增强,显微观察断口形貌呈塑性,电子背射衍射试验表明塑性相为奥氏体。在电脉冲作用下,脆性组元的大电阻产生集中的焦耳热和电流密度,依据Boltzmann分布规律,揭示了薄膜状奥氏体在电压梯度、温度梯度及其产生的压应力梯度综合作用下的形成机理。电脉冲作用斑点不超过0.2 mm,与经典焊后热处理韧化技术相比,显示了电脉冲韧化的局域性特征。创新点:(1)电脉冲处理高强钢焊接热影响区形成了奥氏体。(2)电脉冲处理韧化高强钢焊接热影响区,对邻近组织的性能无影响。 相似文献