材料期刊网

An Easy Way to Quantify the Adhesion Energy of Nanostructured Cu/X (X = Cr, Ta, Mo, Nb, Zr) Multilayer Films Adherent to Polyimide Substrates

Kai Wu , Jin-Yu Zhang , Gang Liu , Jiao Li , Guo-Jun Zhang , Jun Sun

金属学报(英文版) doi:10.1007/s40195-016-0375-4

An approach based on film buckling under simple uniaxial tensile testing was utilized in this paper to quantitatively estimate the interfacial energy of the nanostructured multilayer films (NMFs) adherent to flexible substrates. The interfacial energies of polyimide-supported NMFs are determined to be ~5.0 J/m² for Cu/Cr, ~4.1 J/m² for Cu/Ta, ~2.8 J/m² for Cu/Mo, ~1.1 J/m² for Cu/Nb, and ~1.2 J/m² for Cu/Zr NMFs. Furthermore, a linear relationship between the adhesion energy and the interfacial shear strength is clearly demonstrated for the Cu-based NMFs, which is highly indicative of the applicability and reliability of the modified models.

关键词: niaxial , tensile , testing , Nanostructured , multilayer , films , Flexible , substrates , Buckling , behaviors , Adhesion , energy

Microstructure and Tribological Properties of Plasma-sprayed Nanostructured Sulfide Coating

Yang XU , Yaohui GUAN , Zhongyu ZHENG

材料科学技术（英）

The friction and wear properties of plasma-sprayed nanostructured FeS coating were investigated on an MHK-500 friction and wear tester under both oil lubrication and dry friction condition. The microstructure, worn surface morphology and phase composition of the coating were characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD). It was found that the coating was mainly composed of FeS, a small quantity of Fe1-xS and oxide were also found. The coating was formed by small particles of 50~100 nm in size. The thickness of the coating is approximately 150 μm. The friction-reduction and wear-resistance properties of plasma-sprayed nanostructured FeS coating were superior to that of GCr15 steel substrate. Especially under oil lubrication condition, the friction coefficient of nanostructured FeS coating was 50% of that of GCr15 steel, the wear scar widths of the coating were also reduced to nearly 50% of that of GCr15 steel under high load. The failure of the coating was mainly attributed to plastic deformation under both oil lubrication and dry friction condition.

关键词: Plasma spray , spray , Nanostructured , FeS , Frictio

Layer Thickness-Dependent Hardness and Strain Rate Sensitivity of Cu-Al/Al Nanostructured Multilayers

Ya-Qiang Wang , Zhao-Qi Hou , Jin-Yu Zhang , Xiao-Qing Liang , Gang Liu , Guo-Jun Zhang , Jun Sun

金属学报(英文版) doi:10.1007/s40195-016-0372-7

Cu-Al/Al nanostructured metallic multilayers with Al layer thickness h _Al varying from 5 to 100 nm were prepared, and their mechanical properties and deformation behaviors were studied by nanoindentation testing. The results showed that the hardness increased drastically with decreasing h _Al down to about 20 nm, whereafter the hardness reached a plateau that approaches the hardness of the alloyed Cu-Al monolithic thin films. The strain rate sensitivity (SRS, m), however, decreased monotonically with reducing h _Al. The layer thickness-dependent strengthening mechanisms were discussed, and it was revealed that the alloyed Cu-Al nanolayers dominated at h _Al ≤ 20 nm, while the crystalline Al nanolayers dominated at h _Al > 20 nm. The plastic deformation was mainly related to the ductile Al nanolayers, which was responsible for the monotonic evolution of SRS with h _Al. In addition, the h _Al-dependent hardness and SRS were quantitatively modeled in light of the strengthening mechanisms at different length scales.

关键词: Nanostructured , films , Cu-Al/Al , multilayers , Hardness , Strain , rate , sensitivity , Layer , thickness , dependence

Annealing-induced Grain Refinement in a Nanostructured Ferritic Steel

Limin Wang

材料科学技术（英）

A nanostructured surface layer with a mean ferrite grain size of ~8 nm was produced on a Fe-9Cr steel by means of surface mechanical attrition treatment. Upon annealing, ferrite grains coarsen with increasing temperature and their sizes increase to ~40 nm at 973 K. Further increasing annealing temperature leads to an obvious reduction of ferrite grain sizes, to ~14 nm at 1173 K. The annealing-induced grain refinement is analyzed in terms of phase transformations in the nanostructured steel.

关键词: Nanostructured

Friction and Wear Behaviors of Nanostructured Metals

Zhong HAN , Yusheng ZHANG

材料科学技术（英）

Nanostructured (ns) materials, i.e., polycrystalline materials with grain sizes in the nanometer regime (typically below 100 nm), have drawn considerable attention in the past decades due to their unique properties such as high strength and hardness. Wear resistance of ns materials, one of the most important properties for engineering materials, has been extensively investigated in the past decades. Obvious differences have been identified in friction and wear behaviors between the ns materials and their corresponding coarse-grained (cg) counterparts, consistently correlating with their unique structure characteristics and mechanical properties. On the other hand, the superior tribological properties of ns materials illustrate their potential applications under contact loads. The present overview will summarize the important progresses achieved on friction and wear behaviors of ns metallic materials, including ultrafine-grained (ufg) materials in recent years. Tribological properties and effects on friction and wear behaviors of ns materials will be discussed under different wear conditions including abrasive wear, sliding wear, and fretting wear. Their correlations with mechanical properties will be analyzed. Perspectives on development of this field will be highlighted as well.

关键词: Nanostructured metals , metals , Friction , Wear , Mech

Annealing-induced Grain Refinement in a Nanostructured Ferritic Steel

材料科学技术（英）

关键词: 英文摘要 , 材料科学 , 优秀论文 , 科技学报