Library

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    Influence of the Metal Particle Size on the Crack Growth Resistance in Mullite–Molybdenum Composites (2002)
    Westerville, Ohio : American Ceramics Society
    Journal of the American Ceramic Society 85 (2002), S. 0 
    Details
    ISSN: 1551-2916
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: The R-curve for mullite–molybdenum (32 vol%) composites, which were obtained at 1650°C under reducing conditions with three different Mo average grain sizes (1.5, 3, and 9 μm), was estimated by the indentation-strength method and compared with that monolithic mullite obtained under similar conditions. The composites material exhibited rising R-curve behavior. The composite with larger grain size, however, displayed better damage tolerance and higher resistance to crack growth. Microscopic observation of the crack path revealed, in the composites, the systematic presence of dispersoids acting as bridging sites in the crack wake. Therefore, the increased fracture toughness of these ceramic-matrix composites with adherent ductile phase can be attributed to clamping forces applied by metal ligaments that bridge the crack faces behind the crack front. These clamping forces retard the crack from opening as an external stress is applied. It was inferred that this superior performance of the larger Mo particle size composite can be attributed mainly to more effective bridging of the metal grains. Because of this, a higher applied stress intensity will be required to propagate the crack tip. These results suggest that the rising R-curve should be proportional to the metal grain size, since the grain bridging area is proportional to the metal grain size.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1151-2916.2002.tb00528.x
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Mechanically Stable Monoclinic Zirconia–Nickel Composite (2002)
    Westerville, Ohio : American Ceramics Society
    Journal of the American Ceramic Society 85 (2002), S. 0 
    Details
    ISSN: 1551-2916
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: A dense (〉98% theoretical density), residual-stress-free m-ZrO2/40 vol% nickel composite with K IC∼ 5.4 MPa·m1/2 and ςf∼ 225 MPa has been obtained using a simple wet processing route and subsequent sintering at 1430°C in a 90% argon/10% hydrogen atmosphere. The mechanism for release of internal stresses by the composite developed during the t → m transformation on cooling is explained in terms of plastic flow in the infinite nickel cluster formed at the percolation threshold.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1151-2916.2002.tb00416.x
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Functionally Graded Zircon–Molybdenum Materials without Residual Stresses (2000)
    Westerville, Ohio : American Ceramics Society
    Journal of the American Ceramic Society 83 (2000), S. 0 
    Details
    ISSN: 1551-2916
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: A layered, zircon–molybdenum functionally graded material was obtained by starting from commercial powders of molybdenum (median particle size (d50) of ∼3 μm) and zircon (d50∼ 0.8 μm). Conventional processing led to a material that was free of internal residual stress. The sintering behavior of green compacts with compositions that corresponded to the different layers was studied via dynamic sintering. The thermal expansion coefficients of each layer were measured using conventional dilatometry. The presence of residual stresses was determined using Vickers indentations. Both thermal expansion mismatch and differential shrinkage between the layers were negligible.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1151-2916.2000.tb01220.x
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Electrokinetic Behavior and Stability of Silicon Carbide Nanoparticulate Dispersions (1998)
    Westerville, Ohio : American Ceramics Society
    Journal of the American Ceramic Society 81 (1998), S. 0 
    Details
    ISSN: 1551-2916
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: The stability of aqueous suspensions containing SiC nanoparticles prepared by inductively coupled plasma has been studied. Physicochemical analyses indicated that the as-prepared samples consisted of monocrystalline spherical particles of the 3C-SiC polytype with a mean diameter of about 40 nm. HRTEM clearly showed that the particles were covered by an amorphous surface layer which according to XPS was mainly composed of carbon. DTA and TG analyses showed that the free carbon was eliminated by heating the sample at 650°C in air, but the resulting powder exhibited an excess of amorphous SiO2 on the particle surfaces. This silica coating was leached out by using a 5% HF solution. It has been determined, by evaluating an effective Hamaker constant, that the most stable aqueous suspensions are obtained by using the sample containing the amorphous SiO2 surface layer. Finally, evidence of the presence of a strong hydrophobic force was detected in the original sample and in the one prepared by heating at 650°C and further leaching with HF.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1151-2916.1998.tb02345.x
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Fatigue Crack Growth Behavior in Mullite/Alumina Functionally Graded Ceramics (1998)
    Westerville, Ohio : American Ceramics Society
    Journal of the American Ceramic Society 81 (1998), S. 0 
    Details
    ISSN: 1551-2916
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Mullite/Al2O3 functionally graded ceramics (FGCs) have been obtained by sequential slip casting and subsequently firing at 1650°C in air. Functionally graded layered dense (similar/congruent99% of the theoretical density) compacts, with five different layers with thickness ranging from 670 to 850 µm, were obtained. The layer composition was gradually changed from 100% mullite to 80% mullite/20% alumina. The elastic modulus, the flexure strength, and the fatigue life of the monolithic (80% mullite/20% alumina) and mullite/alumina FGCs were measured by means of four-point bending tests. The mullite/alumina FGCs exhibited lower strength than the monolithic material but the fatigue resistance and reliability were improved in the high cycle fatigue regime. These results were rationalized in terms of the residual stress distribution in the FGCs, which was computed using a description of stresses and strains in the multilayer composite based on the simple beam analysis. The tensile residual stresses which developed in the surfaces were responsible for the lower strength, while the compressive residual stresses within the bulk arrested the fatigue crack and improved the fatigue life of the FGC material.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1151-2916.1998.tb02509.x
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Microstructure and High-Temperature Mechanical Behavior of Alumina/Alumina–Yttria-Stabilized Tetragonal Zirconia Multilayer Composites (1997)
    Westerville, Ohio : American Ceramics Society
    Journal of the American Ceramic Society 80 (1997), S. 0 
    Details
    ISSN: 1551-2916
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Layered composites of alternate layers of pure Al2O3(thickness of 125 μ m) and 85 vol% Al2O3-15 vol% ZrO2 that was stabilized with 3 mol% Y2O3(thickness of 400 μ m) were obtained by sequential slip casting and then fired at either 1550° or 1700°C. Constant-strain-rate tests were conducted on these materials in air at 1400°C at an initial strain rate of 2 × 10-5 s-1. The load axis was applied both parallel and perpendicular to the layer interfaces. Catastrophic failure occurred for the composite that was fired at 1700°C, because of the coalescence of cavities that had developed in grain boundaries of the Al2O3 layers. In comparison, the composite that was fired at 1550°C demonstrated the ductility of the Al2O3+YTZP layer, but at a flow stress level that was determined by the Al2O3 layer.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1151-2916.1997.tb03097.x
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    Evidence of Nearest-Neighbor Ordering in Wet-Processed Zirconia–Nickel Composites (2001)
    Westerville, Ohio : American Ceramics Society
    Journal of the American Ceramic Society 84 (2001), S. 0 
    Details
    ISSN: 1551-2916
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Monolithic zirconia–nickel (ZrO2/Ni) cermets have been prepared by a wet-processing method with nickel volume concentrations of 16%–40%. Microstructural analysis performed on scanning electron microscopy images has revealed evidence of a partial ordering of metallic particles inside the ceramic matrix. This ordering does not appear in mullite/molybdenum cermets. Complex impedance measurements have shown that the percolation threshold of ZrO2/Ni cermets appears at a filling factor (fc) of 0.34, exceeding the theoretical value (fc= 0.16), as a consequence of its microstructural order. Electrical measurements display the expected increase of capacity near the percolation threshold. These results open the possibility to design new devices with the appealing electric, magnetic, and mechanical properties that are predicted by the percolation theory.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1151-2916.2001.tb01030.x
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    Sliding Wear of Alumina/Silicon Carbide Nanocomposites (1999)
    Westerville, Ohio : American Ceramics Society
    Journal of the American Ceramic Society 82 (1999), S. 0 
    Details
    ISSN: 1551-2916
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: The wear resistance of four Al2O3/SiC nanocomposites that contained SiC particles of varying average size (40, 200, and 800 nm) was studied under dry sliding conditions and compared with the results obtained in unreinforced alumina. The wear rate of the alumina and the nanocomposites of equivalent grain size increased as the contact load increased; however, the nanocomposite wear resistance at high contact loads was better than that of the alumina by a factor of 3–5. The wear resistance of the nanocomposites of submicrometer grain size was fairly independent of the contact load, and their wear resistance at high contact loads was up to two orders of magnitude better than that of the alumina. The mechanisms responsible for these behaviors were discussed in terms of the microscopic wear mechanisms that were observed on the worn surfaces.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1151-2916.1999.tb02071.x
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    Microstructural Investigation of the Aging Behavior of (3Y-TZP)–Al2O3 Composites (2005)
    Oxford, UK : Blackwell Science Inc
    Journal of the American Ceramic Society 88 (2005), S. 0 
    Details
    ISSN: 1551-2916
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: The low-temperature autoclave aging behavior of zirconia-toughened alumina composites processed by a classical powder mixing processing route was analyzed using atomic force microscopy (AFM), scanning electron microscopy, and X-ray diffraction (XRD). The transformation was evaluated in terms of nucleation and growth, assessed by XRD. The time–temperature equivalency of the transformation was used to measure an apparent activation energy of the nucleation stage of the transformation of 78 kJ/mol. The microstructural features influencing the transformation were identified, and the influence of the alumina matrix on the transformation was investigated. Transformation progression grain by grain was observed by AFM. Transformation does not only occur in zirconia agglomerates but also in isolated zirconia grains. The matrix could partially inhibit the transformation. This behavior could be rationalized considering the constraining effect of the alumina matrix, shape strain accommodation arguments, and microstructural homogeneity effects.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1551-2916.2005.00221.x
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 10
    Electronic Resource
    Electronic Resource
    Al2O3–ZrO2–SiO2 Ternary Glasses for Molybdenum Oxidation Barriers (2005)
    Oxford, UK : Blackwell Science Inc
    Journal of the American Ceramic Society 88 (2005), S. 0 
    Details
    ISSN: 1551-2916
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: The wettability of binary and ternary glasses belonging to SiO2–Al2O3–ZrO2 diagram has been studied using the sessile drop technique at 1750° and 1800°C. The ternary SiO2–Al2O3–ZrO2 (90–5–5 wt%) glass has proved to be well appropriated as a molybdenum oxidation barrier coating. The addition of 5 wt% of MoO2 slightly improves its wettablity at higher temperatures without affecting its oxidation barrier properties. The Mo comes into the glass network as a mixture of Mo5+, Mo4+, and Mo6+. After oxidation at 1000°C in oxygen atmosphere, the molybdenum remains in the glass network as Mo6+.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1551-2916.2005.00189.x
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...