27 Result(s)

Article

Surface Energy Anisotropy of Diffusion-Induced Ni₃ A1 Crystals

Faceted crystals with well-defined {100}, {110}, and {1111 surfaces were observed in the interdiffusion zone during chemical interdiffusion of Ni/Ni 3 Al diffusion couple in the temperature range of 800°−1200°...

T. C. Chou, Y. T. Chou in MRS Online Proceedings Library (2011)

Article

The Effect of Boron on Microhardness in Ni₃ Al Polycrystals

In a recent MRS symposium, the effect of boron on grain boundary hardness (GBH) in Ni₃Al was reported. Addition of 0.2 at.% of boron decreased the GBH in all three sets of alloys tested (24, 25, and 26 at.% Al). ...

X. R. Qian, Y. T. Chou in MRS Online Proceedings Library (2011)

Article

Wet Oxidation in a Square Sandwich Composite of GaAs/AlAs/GaAs

Wet oxidation in a square sandwich composite, GaAs/AlAs/GaAs, with varying thickness of the AlAs layer was investigated in a temperature range of 400°C–480°C. At a given temperature and time, the oxidation dep...

Sun-Chien Ko, Sanboh Lee, Y.T. Chou in Journal of Electronic Materials (2007)

Article

Chemical stresses induced by grain-boundary diffusion

Based on Whipple-Suzuoka solutions, the chemical stresses induced by grain-boundary diffusion under constant- and instantaneous-source concentrations are investigated. For a finite boundary, the chemical stres...

W. L. Wang, Y. T. Chou, Sanboh Lee in Metallurgical and Materials Transactions A (1998)

Article

Fractal characterization of the fracture surface of a high-strength low-alloy steel

The fractal dimension of fracture surfaces of a high-strength low-alloy steel (ASTM A710) has been measured using different ruler lengths. The fractal dimension increases with increasing impact toughness, E, a...

J. C Hsiung, Y. T Chou in Journal of Materials Science (1998)

Article

Thermal and mechanical properties of porous Y-PSZ/zircon composites

 The thermal and mechanical properties of sintered porous composites of yttria-partially-stabilized-zirconia (Y-PSZ) and zircon (ZrSiO₄) were investigated for a broad range of compositions. Fracture strengths of ...

Y. P. **, Y. T. Chou in Material Research Innovations (1998)

Article

An experimental study of the interaction of internal cracks in PMMA

Internal cracks in polymethyl methacrylate (PMMA) specimens were generated by pulsed laser light. The interactions of coplanar cracks, parallel cracks, and cracks in T and H configurations were investigated. T...

Y. Z LI, Y. T CHOU in Journal of Materials Science (1997)

Article

Analysis of mean square penetration depth in grain boundary diffusion

Exact and approximate expressions for mean square penetration depth (MSPD) in grain boundary diffusion are derived. The MSPDs in boundary diffusion are functionally different from those in lattice diffusion. T...

Y. T. Chou, Y. Z. Li, C. T. Liu in Metallurgical and Materials Transactions A (1996)

Article

On the interaction of internal cracks in polymethyl methacrylate

Y. Z. Li, Y. T. Chou in Journal of Materials Science Letters (1996)

Article

Deformation mechanism map for creep in YBa₂Cu₃O_7−x

A deformation mechanism map with grain size and stress as variables was constructed for creep in YBa₂Cu₃O_7−xat 850 and 950 °C. Theoretical models of Nabarro-Herring, Coble, and power-law creep were used for the c...

J. Yun, M. P. Harmer, Y. T. Chou in Journal of Materials Science (1995)

Article

Growth and Facet Orientations in Single-Phase TiAl Single Crystals

Single crystals of single-phase TiAl alloy (Ti-56 at. % Al) have been grown at 10mm/h solidification rate in an ASGAL FZ-SS35W Optical Floating Zone Furnace. The orientations of the resulting single crystals h...

R. Mahapatra, H. Lin, D. P. Pope, Y. T. Chou in MRS Online Proceedings Library (1994)

Article

Observation of laser-induced internal flaws in PMMA

B. Zhou, Y. T. Chou in Journal of Materials Science Letters (1993)

Article

Alloy softening in Ni₃Al polycrystals

The alloying effect of boron on localized deformation in Ni₃Al polycrystals containing 24–26 at% AI was studied using microhardness indentation. Alloy softening was observed both along the grain boundaries and in...

X. R. Qian, Y. T. Chou in Journal of Materials Science (1992)

Article

Cation interdiffusion between thick film of YBa₂Cu₃O_7-δ and ceramic substrate

Thick films of superconducting oxides, YBa₂Cu₃O_7-δ, were successfully made by conventional screen-printing technology on Al₂O₃, MgO, and ZrO₂ substrates. Interdiffusion between the superconductive film and substr...

X. M. Li, Y. T. Chou, Y. H. Hu, C. L. Booth in Journal of Materials Science (1991)

Article

Uphill diffusion in YBa²Cu³O^7-δ thick film on Al₂O₃ substrate

X. M. Li, Y. T. Chou, Y. H. Hu, C. L. Booth in Journal of Materials Science Letters (1990)

Article

Interfacial Failure In Ti/Sio₂ and Ti/AIN System And Temperature Dependence Of Hardness Of AIN

The load dependence of interracial failure induced by microindentation has been studied. It is demonstrated experimentally that substrate lateral defects induced by indentation contribute significantly to inte...

T. Liu, R. Notis, Y. T. Chou in MRS Online Proceedings Library (1989)

Article

Grain Boundary Softening in Boron-Doped Ni₃Al

The effect of 0.2 at.% boron on grain boundary hardness in Ni₃Al containing 24 to 26 at.% Al was studied. Normal grain boundary hardening was observed in all alloys with and without boron. However, the addition o...

X. R. Qian, Y. T. Chou in MRS Online Proceedings Library (1988)

Article

The effect of Sn, AI, and N on the hot ductility of a carbon-manganese steel between 700° and 1200 °C

The effect of Sn and Al-N additions on the hot ductility of a C-Mn steel has been investigated in a series of laboratory melted steels. The addition of either Sn or Al-N produced a similar degree of ductility ...

W. T. Nachtrab, Y. T. Chou in Metallurgical Transactions A (1988)

Article

High temperature ductility loss in carbon-manganese and niobium-treated steels

The causes of embrittlement in several plain carbon-manganese and niobium-treated steels between 800 and 1200 °C have been investigated. Tensile ductility was measured as a function of temperature and strain r...

W. T. Nachtrab, Y. T. Chou in Metallurgical Transactions A (1986)

Article

Equilibrium shapes of Ni₃Al crystallites formed during diffusion anneal

T. C. Chou, Y. T. Chou in Journal of Materials Science Letters (1985)