Growth behaviors of aluminum nitride in steel during laser nitriding: Insights into interfacial energy and segregation throughout its growth habit

Modern polishing, precision machining and microindentation techniques allow the processing and mechanical characterization of ceramics at nanometric scales and within entirely plastic deformation regimes. The mechanical response of most ceramics to such highly constrained contact is not predictable from macroscopic properties and the microstructural deformation patterns have proven difficult to characterize by the application of any individual technique. In this study, TEM techniques of contrast analysis and CBED are combined with stereographic analysis to construct a three-dimensional microstructure deformation map of the surface of a perfectly plastic microindentation on macroscopically brittle aluminum nitride.The bright field image in Figure 1 shows a lg Vickers microindentation contained within a single AlN grain far from any boundaries. High densities of dislocations are evident, particularly near facet edges but are not individually resolvable. The prominent bend contours also indicate the severity of plastic deformation. Figure 2 is a selected area diffraction pattern covering the entire indentation area.

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CBED analysis of impurity distributions in AlN

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100174205 ◽

1990 ◽

Vol 48 (4) ◽

pp. 214-215

Author(s):

Daniel Callahan ◽

G. Thomas

Keyword(s):

Aluminum Nitride ◽

Bulk Material ◽

Strong Dependence ◽

Lattice Parameter ◽

Promising Technique ◽

Nitride Ceramics ◽

Surface Phases ◽

Convergent Beam ◽

Oxygen Impurities

Oxygen impurities may significantly influence the properties of nitride ceramics with a strong dependence on the microstructural distribution of the impurity. For example, amorphous oxygen-rich grain boundary phases are well-known to cause high-temperature mechanical strength degradation in silicon nitride whereas solutionized oxygen is known to decrease the thermal conductivity of aluminum nitride. Microanalytical characterization of these impurities by spectral methods in the AEM is complicated by reactions which form oxygen-rich surface phases not representative of the bulk material. Furthermore, the impurity concentrations found in higher quality ceramics may be too low to measure by EDS or PEELS. Consequently an alternate method for the characterization of impurities in these ceramics has been investigated.Convergent beam electron diffraction (CBED) is a promising technique for the study of impurity distributions in aluminum nitride ceramics. Oxygen is known to enter into stoichiometric solutions with AIN with a consequent decrease in lattice parameter.

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Microstructural changes of Aluminum Nitride after laser irradiation and electroless copper deposition

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100170918 ◽

1994 ◽

Vol 52 ◽

pp. 636-637

Author(s):

S. Cao ◽

A. J. Pedraza ◽

L. F. Allard

Keyword(s):

Aluminum Nitride ◽

Laser Irradiation ◽

Electroless Deposition ◽

Thermal Evaporation ◽

Surface Region ◽

Near Surface ◽

Laser Patterning ◽

Electroless Copper ◽

Excimer Laser Irradiation ◽

Laser Effect

Excimer-laser irradiation strongly modifies the near-surface region of aluminum nitride (AIN) substrates. The surface acquires a distinctive metallic appearance and the electrical resistivity of the near-surface region drastically decreases after laser irradiation. These results indicate that Al forms at the surface as a result of the decomposition of the Al (which has been confirmed by XPS). A computer model that incorporates two opposing phenomena, decomposition of the AIN that leaves a metallic Al film on the surface, and thermal evaporation of the Al, demonstrated that saturation of film thickness and, hence, of electrical resistance is reached when the rate of Al evaporation equals the rate of AIN decomposition. In an electroless copper bath, Cu is only deposited in laser-irradiated areas. This laser effect has been designated laser activation for electroless deposition. Laser activation eliminates the need of seeding for nucleating the initial layer of electroless Cu. Thus, AIN metallization can be achieved by laser patterning followed by electroless deposition.

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Scanning Transmission Electron Microscopy of Polyethylene Crystals

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s1431927600001069 ◽

1980 ◽

Vol 38 ◽

pp. 242-245

Author(s):

F. Khoury ◽

L. H. Bolz

Keyword(s):

Electron Microscopy ◽

Transmission Electron Microscopy ◽

Crystallization Temperature ◽

Scanning Transmission Electron Microscopy ◽

Growth Habit ◽

Lateral Growth ◽

Scanning Transmission Electron ◽

Transmission Electron ◽

Scanning Transmission ◽

Growth Habits

The lateral growth habits and non-planar conformations of polyethylene crystals grown from dilute solutions (<0.1% wt./vol.) are known to vary depending on the crystallization temperature.1-3 With the notable exception of a study by Keith2, most previous studies have been limited to crystals grown at <95°C. The trend in the change of the lateral growth habit of the crystals with increasing crystallization temperature (other factors remaining equal, i.e. polymer mol. wt. and concentration, solvent) is illustrated in Fig.l. The lateral growth faces in the lozenge shaped type of crystal (Fig.la) which is formed at lower temperatures are {110}. Crystals formed at higher temperatures exhibit 'truncated' profiles (Figs. lb,c) and are bound laterally by (110) and (200} growth faces. In addition, the shape of the latter crystals is all the more truncated (Fig.lc), and hence all the more elongated parallel to the b-axis, the higher the crystallization temperature.

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Evidence for the involvement of jasmonic acid in the control of the stem-growth habit of soybean plants

Physiologia Plantarum ◽

10.1034/j.1399-3054.1991.830104.x ◽

1991 ◽

Vol 83 (1) ◽

pp. 22-26 ◽

Cited By ~ 1

Author(s):

Yasunori Koda ◽

Koichi Yoshida ◽

Yoshio Kikuta

Keyword(s):

Jasmonic Acid ◽

Growth Habit ◽

Stem Growth ◽

Soybean Plants

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FloRunTM ‘331’ Peanut Variety

EDIS ◽

10.32473/edis-ag42-2019 ◽

2019 ◽

Vol 2019 (1) ◽

Author(s):

Barry L. Tillman

Keyword(s):

Seed Size ◽

Growth Habit ◽

Yield Potential ◽

High Yield ◽

University Of Florida ◽

High Oleic ◽

Central Stem ◽

Research And Education ◽

The University ◽

High Yield Potential

FloRunTM ‘331’ peanut variety was developed by the University of Florida, Institute of Food and Agricultural Sciences, North Florida Research and Education Center near Marianna, Florida. It was released in 2016 because it combines high yield potential with excellent disease tolerance. FloRunTM ‘331’ has a typical runner growth habit with a semi-prominent central stem and medium green foliage. It has medium runner seed size with high oleic oil chemistry.

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