International Journal of Materials Research

Published by De Gruyter

Volume 95 Issue 2

February 2004

Issue of International Journal of Materials Research

Contents
Journal Overview

Publicly Available December 20, 2021

Frontmatter

Page range: 69-69

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Articles B_Basic

December 20, 2021

Thermodynamic modeling of the Rh–Zr system

Zhenmin Du

Page range: 70-75

Abstract

The Rh–Zr system has been critically assessed by means of the CALPHAD technique. The solution phases (liquid, body-centered cubic (Zr), face-centered cubic (Rh) and hexagonal close-packed (Zr)) were modeled with the Redlich – Kister equation. The intermetallic compounds Rh 3 Zr, Rh 5 Zr 3 , Rh 4 Zr 3 , and RhZr, which have a homogeneity range, were treated by the formulae (Rh, Zr) 3 (Rh, Zr), Rh 5 (Rh, Zr) 3 , (Rh, Zr) 4 Zr 3 , and Rh(Rh, Zr) by a two-sublattice model with Rh and Zr or Rh on the first sublattice, Rh and Zr or Zr on the second one, respectively. The intermetallic compound RhZr 2 was treated as a stoichiometric compound. A set of self-consistent thermodynamic parameters of the Rh–Zr system was obtained.

December 20, 2021

Ni grain boundary diffusion in coarse-grained Fe-40 wt.% Ni alloy and comparison with Ni diffusion in the nanocrystalline alloy

Y.-S. Kang, J.-S. Lee, S. V. Divinski, Chr. Herzig

Page range: 76-79

Abstract

63 Ni grain boundary (GB) diffusion in polycrystalline γ-Fe – Ni alloy was measured by the conventional radiotracer method. The double product P = δ x D gb ( δ is the GB width and D gb is the GB diffusivity) was found to follow the Arrhenius relationship P =1.31×10 −13 × exp(−157 kJ mol −1 / RT ) m 3 /s, where R is the gas constant and T is the temperature. The results in the coarse-grained material (grain size d ≈ 0.5 mm) were discussed in comparison with our previous investigation of Ni diffusion in a nanocrystalline alloy ( d ≈ 100 nm) of the same composition.

December 20, 2021

Crystallization kinetics of an amorphous Zr₇₀Cu₂₀Ni₁₀ alloy

Huan-Rong Wang, Yu-Lai Gao, Guang-Hui Min, Ying Chen, Yi-Fu Ye

Page range: 80-83

Abstract

Differential scanning calorimetry and transmission electron microscopy (TEM) were employed to investigate the crystallization kinetics of an amorphous Zr 70 Cu 20 Ni 10 alloy. It has been found that the crystallization process is mainly controlled by three-dimensional nucleation and growth with an increasing nucleation rate. The activation energy for crystallization is approximately 388 kJ/mol. TEM observations confirmed that the primary precipitation phase during the isothermal crystallization process is the Zr 2 Ni phase, which can be partly attributed to the stronger binding nature between Zr and Ni atoms than that between Zr and Cu atoms.

December 20, 2021

Oxidation-induced cavity formation in binary β-NiAl alloys

D. Zimmermann, M. Bobeth, M. Rühle, D. R. Clarke

Page range: 84-90

Abstract

Previously, it has been established that oxidation-induced cavitation of binary NiAl alloys occurs primarily when Nirich compositions are oxidized. In this work it is shown that at 1100 °C cavities form principally during the very early stages of oxidation for these compositions. During this time, the growing oxide is a transient, theta-alumina whereas on the Al-rich compositions the growing oxide rapidly transforms to alpha alumina. It is concluded that cavity formation is associated with tensile stresses generated by the flux divergence created by the outward diffusion of Al during the growth of theta-alumina and the inward diffusion of nickel. Once the transient oxide transforms to alpha alumina, the outward flux of aluminum is decreased and with it the flux divergence. Values for the inter-diffusion coefficients for the alloys investigated, derived from the diffusion profiles, are also reported.

Articles A_Applied

December 20, 2021

Influences of counterface materials and reinforcements on the sliding wear of copper matrix composites

Yongzhong Zhan, Guoding Zhang, Zhenyi Liu

Page range: 91-96

Abstract

The influences of counterface materials and reinforcements on the sliding wear behavior of copper matrix composites have been investigated. Experiments were performed using a block-on-ring type wear machine on which SiC/Cu and (SiC+Gr)/Cu hybrid composites were slid against various counterfaces, i. e. GCr15 bearing steel, 45 medium carbide steel and AlSi alloy. Experimental results show that increasing counterface hardness is in favor of the establishment of a wear resistant mechanically mixed layer (MML) on SiC/ Cu composite, while massive materials transfer and seizure take place when tested against soft counterface. The wear resistance of hybrid composite is improved by forming a graphite-rich MML, and the hardness of steel counterfaces does not influence the wear behavior obviously. The graphite film formed on the two sliding surfaces alleviates materials transfer and avoids the occurrence of seizure with soft counterface.

December 20, 2021

Model of artificial neural network for complex data analysis in slag glass-ceramic

Hongyuan Sun, Qiye Wen, Peixin Zhang, Jianhong Liu, Qianling Zhang, Xiangzhong Ren, Weiliang Hong, Bo Wei

Page range: 97-101

Abstract

An artificial neural network was applied to slag glass-ceramic complex data analysis. A three-layer feedforward network was built with a new robust learning algorithm based on a concept of entire error modifying . These studies indicate that the network has an excellent learning ability when its topology is M –(2 M + 1) – 1 and when an appropriate study error was chosen. Research shows that this slag glass-ceramic neural network is robust, accurate and stable in complex data analysis, and can disclose the relationship of elemental compositions, processing parameters and material properties of slag glass-ceramic effectively.

December 20, 2021

Quantitative investigation of material erosion caused by high-pressure discharges in air and nitrogen

A. Lasagni, F. Soldera, F. Mücklich

Page range: 102-108

Abstract

Single-spark erosion experiments were conducted in different pure metal samples. The samples were used as the cathode, and a platinum electrode was used as the anode. The sparks were produced at high pressure and room temperature, having at this conditions a breakdown phase (ca. 100 ns) and an arc phase (several hundreds of μs). The crater volumes on the different materials were correlated with several properties of materials, in view of different models of material erosion related to melting enthalpy, vaporization enthalpy and sublimation energy. It was found that the quotient between the eroded volume and the spark energy correlates well with a function of the energy necessary to heat the material up to the melting point and to melt it. The particle ejection model can be used to explain this process. Moreover, it was found that the crater shape is related to the surface tension of the molten material. These investigations may be relevant for the development of high-performance materials for electrode and contact applications.

December 20, 2021

Role of alloying elements on machinability of plastic-molding steels

Masahide Umino, Tomoaki Sera, Yutaka Ikenaga, Yasutaka Okada, Reizo Murakami, Shigeharu Tubakino

Page range: 109-114

Abstract

The influence of silicon and other alloying elements of plastic-molding steels on machinability in face-milling and ball-nose end-milling was investigated. Increase of silicon content decreased the adhesion of chips to a tool and as a result, tool life increased in a dry cutting condition. Vanadium had a similar effect, especially at relatively low cutting speed. To understand these phenomena, the chip surface was analyzed. From these results, it is proposed that low melting temperature oxides of the Fe–Si–O and Fe–V–O systems are formed on the chip surface of high-silicon steel and vanadium-added steel; these oxides lubricate the interface between chip and tool. On the other hand, manganese and chromium that on believed to are form the Fe–Mn–O and Fe–Cr–O oxide film of high melting temperature reduced the lubrication effect. Carbon also decreased tool life due to an increase of pearlite, while the addition of sulfur did not influence tool life.

December 20, 2021

A simple model for the strength and elongation of ultra-fine grained low carbon steels

S. X. Li, G. Y. Li, Y. Q. Weng

Page range: 115-119

Abstract

The documented experimental results show that grain refinement can not substantially improve the elongation but the strength of low carbon steels, particularly when the grain size is smaller than 1 μm. A simple model of geometrically necessary dislocations and statistically-stored dislocations is proposed to account for the effects of grain refinement on the yield strength and uniform elongation of ultrafine grained low carbon steels. In this model, both grain boundary and precipitate strengthening mechanisms were considered. It is shown that both grain and precipitate refinements are necessary to improve the strength and elongation of materials.

Notifications/Mitteilungen

December 20, 2021

Personal/Personelles

Page range: 120-122

December 20, 2021

Conferences/Konferenzen

Page range: 122-122

About this journal

The International Journal of Materials Research (IJMR) publishes original high quality experimental and theoretical papers and reviews on basic and applied research in the field of materials science and engineering, with focus on synthesis, processing, constitution, and properties of all classes of materials. Particular emphasis is placed on microstructural design, phase relations, computational thermodynamics, and kinetics at the nano to macro scale. Contributions may also focus on progress in advanced characterization techniques.
All articles are subject to thorough, independent peer review.

Volume 95 Issue 2

Issue of International Journal of Materials Research

Frontmatter

Thermodynamic modeling of the Rh–Zr system

Abstract

Ni grain boundary diffusion in coarse-grained Fe-40 wt.% Ni alloy and comparison with Ni diffusion in the nanocrystalline alloy

Abstract

Crystallization kinetics of an amorphous Zr70Cu20Ni10 alloy

Abstract

Oxidation-induced cavity formation in binary β-NiAl alloys

Abstract

Influences of counterface materials and reinforcements on the sliding wear of copper matrix composites

Abstract

Model of artificial neural network for complex data analysis in slag glass-ceramic

Abstract

Quantitative investigation of material erosion caused by high-pressure discharges in air and nitrogen

Abstract

Role of alloying elements on machinability of plastic-molding steels

Abstract

A simple model for the strength and elongation of ultra-fine grained low carbon steels

Abstract

Personal/Personelles

Conferences/Konferenzen

Crystallization kinetics of an amorphous Zr₇₀Cu₂₀Ni₁₀ alloy