| Vapor Deposition Equipment and Thin Film Processing |
AUG 96 |
57 pages |
| Authors:
P. J. Gielisse; H. Niculescu; Y. Xu; N. Bai; M. Tu; FLORIDA AGRICULTURAL AND MECHANICAL UNIV TALLAHASSEE
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 | Work under the contract has provided a vapor deposition facility for the generation of thin films and film structures (devices) for structural and electronic applications. Efforts have been expanded into the actual deposition of films in the systems AlN, (Al,B)N, c-BN (cubic boron nitride) and Si-Al-O-N. We report on the resultant physical, chemical, materials and electronic properties and surface characteristics of the films. In certain cases multilayer film structures have ... |
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| The Notch-Embrittlement of Ductile Intermetallic Compounds |
1994 |
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| Authors:
E. M. Schulson; Y. Xu; THAYER SCHOOL OF ENGINEERING HANOVER NH
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 | This paper concerned metals in some important way and contained information about, utilized, or discussed these subjects: basic topics: experimental materials and material types: al3sc, ni-24al, ni3al, zr3al materials related terms: aluminum addition, boron addition, embrittlement, fracture toughness, grain boundary cracking, grain boundary sliding, hydrogen embrittlement, intergranular fracture, modulus of elasticity, optical microscopy, poissons ratio, sem, tem, tensile yield strength, triaxial stress, ultimate tensile strength, work hardening rate testing and ... |
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| Nucleation and Growth in the Initial Stage of Metastable Titanium Disilicide Formation |
93 |
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| Authors:
Z. Ma; Y. Xu; L. H. Allen; S. Lee; ILLINOIS UNIV AT URBANA DEPT OF MATERIALS SCIENCE AND ENGINEERING
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| Initial stage of the C49-TiSi2 formation was investigated at 530 C and at a rate of 10 C/m using transmission electron microscopy. Morphological studies reveal that the C49 phase first separately nucleates at the interface between amorphous silicide and crystalline silicon, then followed by simultaneous lateral and vertical growth. The growth proceeds very fast until the formation of a continuous layer of C49-TiSi2. Local chemical analysis shows that the composition ... |
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| Nb-Ti-Al Ternary Intermetallic Alloys---A Potential High Temperature Ordered Alloy System |
91 |
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| Authors:
G. Chen; Z. Sun; X. Xie; Y. Ren; Y. Xu; BEIJING UNIV (CHINA)
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| For ternary intermetallic alloys in the Nb-Ti-Al system, fundamental crystallographic structure, phase constitution map, density-composition dependence, oxidation resistance, and mechanical behavior were examined; these alloys show low density, high melting point, good and improvable oxidation resistance, and superb high temperature strength, but exhibit room temperature brittleness. |
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| The Yield Strength of Off-Stoichiometric Ni3Al With and Without Boron |
91 |
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| Authors:
E. M. Schulson; Y. Xu; P. R. Munroe; S. Guha; I. Baker; DARTMOUTH COLL HANOVER NH
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| Compression tests have established that the addition of 0.3 at% boron does not significantly affect the contribution of the grain boundaries to the yield strength of Al-rich (26 at% Al) Ni3Al; in contrast, the boundary contribution is reduced by 42% when the same amount of boron is added to Ni-rich (24 at%) Ni3Al; these results are interpreted within the context of the structure and chemistry of the grain boundaries and, ... |
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| Optical Properties of the Vanadium Oxides |
90 |
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| Authors:
J. C. Parker; U. W. Geiser; D. J. Lam; Y. Xu; W. Y. Ching; ARGONNE NATIONAL LAB IL MATERIALS SCIENCE AND TECHNOLOGY DIV
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| The optical properties of VO2 and V2O5 were determined using spectroscopic ellipsometry. The unique physical properties of these materials will be presented and discussed in conjunction with the materials electronic band structure determined by calculations using the orthogonalized linear combination of atomic orbitals method. |
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| Reflection by Defective Diffusion Bonds |
15 AUG 89 |
7 pages |
| Authors:
J. D. Achenbach; Y. Xu; NORTHWESTERN UNIV EVANSTON IL CENTER FOR QUALITY ENGINEERING AND FAILURE PREV ENTION
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| The reflection of ultrasonic wave motion by planar defect distributions is investigated in this paper, with a view towards a method to detect and characterize bond-plane defects and with an ultimate objective of providing information on the bond strength of metal-to-metal bonds. The paper is primarily concerned with an approximate approach to analyze reflection by cavities and cracks which are distributed in a bond plane. The results show some of ... |
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| Accelerating Effect and Critical pH Value of Occluded Cell Corrosion Within Pits, Crevices, or Stress Corrosion Cracks |
AUG 88 |
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| Authors:
J. Zuo; Z. Jin; R. Sun; Y. Xu; X. Feng
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| Simulated occluded solutions were used to study the accelerating effect within the pits, crevices, or stress corrosion cracks for the system of 18-8 steel in chloride ion solution. A critical pH value of about 1.3 (1.5 M chloride ions) was found when the corrosion rate started to accelerate rapidly as the pH value continued to decrease. The rise of external potential above the critical potential is only necessary at the ... |
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| Investigation of Chemical and Electrochemical Changes Within Corrosion Crevices and Cracks of 18-8 Stainless Steel in Chloride Solution |
84 |
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| Authors:
J. Zuo; Z. Jin; S. Zhang; Y. Xu; G. Wang; BEIJING INST OF CHEMICAL TECHNOLOGY (CHINA)*
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| The changes within corrosion crevices or cracks of 18-8 stainless steel in NaCl solution were studied with simulated occluded cells. The tests were conducted either galvanostatically or potentiostatically, with or without stress. The interrelations between currents, Cl ion migration and pH values were evaluated. A linear relationship existed between Cl ion migration and currents. While each faraday passed almost always 1/2 g-eq. of Cl ion migrated into the occluded cell. ... |
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