李化龙
,
黄元伟
,
柳襄怀
,
张允书
腐蚀科学与防护技术
用离子束增强沉积方法,在304不锈钢表面上制备了Si,Y—Si,Al,Y-Al薄膜,研究了它们在950℃、1050℃空气中的氧化,并采用EPMA及SEM等技术分别对氧化产物进行了分析。对离子束增强沉积薄膜样品的抗氧化性、SiO2膜的形成过程及Y的作用进行讨论。
关键词:
离子束增强沉积
,
Al
,
Si
,
Y
,
Oxidation
黄忠平
,
彭晓
,
王福会
金属学报
用复合电沉积的方法制备出新型的Cu-30Ni-20Cr纳米复合镀层，该镀层的组织结构与Cu-Ni-Cr三元合金不同，是由Cu-Ni基固溶体（晶粒尺寸为~60nm）和纳米Cr颗粒（平均尺寸~28nm）组成。与相同的工艺条件下制备的Cu-40Ni合金镀层相比，Cu-30Ni-20Cr纳米复合镀层在800℃空气中氧化速率显著降低，这是由于它能迅速形成一层连续、致密的Cr2O3膜。本文对Cr颗粒在Cu-30Ni-20Cr纳米复合镀层高温氧化过程中所起的作用进行了讨论。
关键词:
电沉积
,
Cu-Ni-Cr nanocomposite film
,
Oxidation
,
null
贡国良
,
冼爱平
金属学报
本文用观察液态锡表面氧化行为和撇取表面氧化渣的方法研究了微量元素 Ge 对液态 Sn在 大气和250 ℃条件下表面抗氧化性能的影响，并与纯锡的氧化行为进行对比；配合 X 射线光电子能谱仪（XPS）、扫描电子显微镜（SEM） 研究了合金表面元素的含量、价态，及合金氧化后的表面形貌。结果表明当微量元素 Ge 浓度达到0.01 wt% 时，大气下液态锡表面具有很好的抗氧化性能， 同时微量元素元素在液态锡表面高度富集。XPS分析表明表面富集的Ge为氧化态，初步确定其以4价氧化物形式存在。作者认为，静态液面氧化时，Ge在液态锡中迅速偏析，并形成一种保护性的致密氧化膜，是提高液态锡的抗氧化性能的原因。
关键词:
锡
,
Oxidation
Zhengyi JIANG
,
Weihua SUN
,
Jianning TANG
,
Dongbin WEI
,
Kiet A.TIEU
材料科学技术（英）
Deformation characteristics of the oxide scale in hot strip mill have not been quantified before and the principle of the effect of oxide scale deformation in the roll bite on strip surface roughness has not yet been revealed. In this paper, analysis of the thin secondary oxide scale formed in hot metal rolling and its surface roughness micro deformation is carried out by experiments and finite element analysis. Simulation results are compared with the measured values, which show that they are in close agreement. Surface roughness transfer during hot metal rolling is also discussed.
关键词:
Oxidation
,
null
,
null
,
null
Wei Yan
材料科学技术（英）
High-temperature titanium alloy for aeroengine compressor applications suffers from high-temperature oxidation and environmental corrosion, which prohibits long-term service of this kind alloy at temperatures above 600°C. In an attempt to tackle this problem, Ti-48Al (at. pct) and Ti-48Al-12Cr (at. pct) protective coatings were plated on the substrate of alloy Ti-60 by arc ion plating (AIP) method. Isothermal and cyclic oxidation tests were performed in static air at elevated temperatures. Phase composition, morphology of the coatings and distribution of elements were investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive X-ray analysis (EDX). The results showed that the Ti-48Al coating exhibited good isothermal oxidation resistance during exposure at 800°C, but poorer resistance against oxidation at 900°C. By contrast Ti-48Al-12Cr coating demonstrated excellent isothermal oxidation resistance at both temperatures. Cyclic oxidation tests performed at 800°C indicated that both coatings demonstrated good cyclic oxidation resistance and no spallation of coatings was observed. But at 900°C only Ti-48Al-12Cr coating demonstrated excellent cyclic oxidation resistance.
关键词:
Oxidation
沈嘉年
,
周龙江
,
李铁藩
,
江竹海
,
滕玉国
腐蚀科学与防护技术
本工作研究了两种Ti_3Al(α_2基)金属间合金(Ti22Al-2Mn,Ti26Al-4Nb)粉末包装渗铝涂层及其900℃恒温与循环氧化行为。通过渗铝处理,在合金表面可获得与基体结合良好的TiAl_3涂层,以NH_4F作活化剂,经800℃,2h渗铝后,含Mn合金上的渗铝层界面平直,厚度均匀,约3μpm厚。在相同条件下,含Nb合金上的渗层界面呈波浪形,厚度不均匀。两种合金上的渗铝层都存在贯穿裂缝。经900℃恒温与循环氧化实验测定了渗铝与未渗铝合金的氧化动力学,渗铝后合金的抗氧化性能显著提高,讨论了渗铝层的
关键词:
Ti_3Al金属间合金
,
TiAl_3 Coating
,
Oxidation
Chungen ZHOU
,
Jingsheng YU
,
Shengkai GONG
,
Huibin XU
材料科学技术（英）
The oxidation of specimens with thermal barrier coating (TBC) consisted of nickel-base superalloy, low-pressure plasma sprayed Ni-28Cr-6Al-0.4Y (wt pct) bond coating and electron beam physical vapor deposited 7.5 wt pct yttria stabilized zirconia (YSZ) top coating was studied at 1050℃ respectively in flows of O2, and mixture of O2 and 5%H2O under atmospheric pressure. The thermal barrier coating has relatively low oxidation rate at 1050℃ in pure O2. Oxidation rate of thermal barrier coating in the atmosphere of O2 and 5%H2O is increased The oxidation kinetics obeys almost linear law after long exposure time in the presence of 5% water vapor. Oxide formed along the interface between bond coat and top coat after oxidation at 1050℃ in pure O2 consisted of Al2O3, whereas interfacial scales formed after oxidation at 1050℃ in a mixture of O2 and 5%H2O were mainly composed of Ni(Al,Cr)2O4,NiO and Al2O3. It is suggested that the effect of water vapor on the oxidation of the NiCrAlY coating may be attributed to the increase in Ni and Cr ions transport in the oxides.
关键词:
Oxidation
,
null
,
null
Rong TU
,
Takashi GOTO
材料科学技术（英）
The oxidation behavior of Hastelloy-XR alloy was investigated to obtain the optimum surface condition for corrosion-resistant glass-coatings. The surface morphology of oxide scales changed significantly with variation of temperature and oxygen partial pressure. The oxidation kinetics was mainly parabolic independent of oxidation conditions. The oxide scales were consisted of inner Cr2O3 and outer spinel layers. The phase component of spinel layers were Mn1.5Cr1.5O4 and (Mn,Ni)(Cr,Fe)2O4 for the oxygen partial pressures po2< 10kPa and po2>10kPa, respectively. The optimum oxidation condition to obtain an oxide scale for well-adhered glass-coating to the substrate was 1248K and po2=0.01kPa for the oxidation time of 43ks.
关键词:
Oxidation
,
null
,
null
Hyung Hoon Kim Jun Ho Kim Jin Young Moon Ho Seong Lee Jeong Joo Kim Young Suck Chai
材料科学技术（英）
The oxidation characteristics for Zircaloy-4 and Zirlo in the temperature range of 700−1200°C under steam supply condition were investigated by using a modified thermo-gravimetric analyzer. The specimens were oxidized for 3600 s at each temperature and then quenched in a furnace. The oxidation rate constants were measured from the weight gains to evaluate the oxidation behavior in Zircaloy-4 and Zirlo. The weight gain rates of Zirlo were lower than those of Zircaloy-4, leading to the low rate constants. The different oxidation behaviors between both cladding materials were considered to be due to the difference in their chemical compositions.
关键词:
Zircaloy-4
,
Zirlo
,
Oxidation
