25 μm thick Upilex films (registered UBE trademark) were carbonized, then graphitized at various temperatures up to 2800 °C and studied by optical and electron microscopies. While the graphitizing behavior of Kapton films is similar to that of anthracites, Upilex graphitization is erratic from one film to the other. The thickness of the better graphitizing Upilex films decreases as the anisotropy increases. Their graphitization occurs at a relatively low temperature (2100 °C), because the oxygen is entirely labile (no cross-linking). Non-graphitizing films are obtained when oxygen remains stable as the heat-treatment temperature (HTT) increases. They stay optically isotropic and microporous without flattening, and even show a limited swelling instead of a thinning. This behavior is attributed to the random mobility of the imide part of the molecule when carbonization starts.

Pipes or hollow cylinders in the Bi-Sr-Ca-Cu-O system were found to be fabricated easily by inspiring or sucking the low viscosity melt into a cold silica glass tube. The outer part of the cast rod-like melt solidified, and the inner hot low-viscosity part of the rod melt was expired. The precursor pipes were reheated at 800 °C for 50 h in air, resulting in the formation of superconducting (Tc = 87 K) pipes which were of smooth surface without machining and high bending strength (100–150 MPa).

We report the preparation of the quasicrystalline particle-dispersed Al base composite alloys for the first time. Icosahedral AlCuFe quasicrystalline (i-AlCuFe) particles were homogeneously dispersed in a crystalline Al matrix using a novel process which combined mechanical alloying and hot press techniques. Hardness of the composite alloy increases with increasing volume fraction of the i-AlCuFe particle, i.e., increases from 25 kg/mm2 for pure Al to about 120 kg/mm2 for a 25 vol. % i-AlCuFe particle dispersed alloy.

The synthesis of poly crystalline boron nitride films, with β-rhombohedral boron crystallites, was accomplished with BCl3–NH3–H2 in a tungsten hot filament chemical vapor deposition apparatus. Raman spectra and XRD results revealed that the crystal structure of the boron nitride films is similar to rhombohedral boron carbide B4C. The composition of these crystallites by XPS was found to give a ratio of boron to nitrogen of 3 : 1 . These results suggest that the boron nitride crystals obtained in this work are previously unreported compounds of a rhombohedral boron-rich boron nitride, analogous to boron carbide, B4C.

The fatigue behavior of ferroelectric PZT capacitors with Ru and RuO x electrodes was studied. These capacitors show no sign of fatigue out to 1 X 1011 cycles, in sharp contrast to the degradation typically observed with Pt electrodes. Compared to Pt electrodes, the initial polarization was lower, but after fatiguing the polarization was comparable to or larger than that for Pt electrodes. Differences in polarization in response to switching and nonswitching pulses greater than 10 μC/cm2 were observed at 1 X 1011 cycles.

When polycarbonate is loaded in tension at room temperature to failure, a certain percentage of the chains are believed to undergo cleavage due to the constraints of entanglements. We present direct evidence that accompanying fracture of polycarbonate, CO molecules are released due to bond scissions.

Chemical interaction between ceramic Y2O3 and Y - Ba-Cu-O liquid with composition close to that of the ternary eutectic is discussed. Intense interaction is observed in the range 930–960 °C that results in the formation of Y2BaCuO5 above 940 °C and YBa2Cu3O6+x plus CuO below 940 °C. At the interface with Y2O3 there is an additional portion containing Y2Cu2O5 or YCuO2. This temperature threshold is exactly that of the peritectic reaction Y2BaCuO5 + L(pl) → YBa2Cu3O6+x + CuO which then appears to control this chemical interaction. The microstructure of the transformed area is oriented in a way that may be used for texturing or crystal growing.

High quality Al-Cu-Fe quasicrystals have been studied at the atomic level with a high resolution microscope operating at 400 kV. When the incident beam is parallel to the fivefold axis, experimental bright-field images in thin regions of the specimen are found to be of two types, depending on the electron optical parameters employed. One of these images is of greater contrast than the other, but both types yield decagon-like image features. Close agreement is found between both types of contrast-enhanced micrographs and microscope image simulations of a realistic atomic model. This model involves the placement of overlapping Mackay icosahedra on a perfect quasicrystalline network. The limitation of resolving the projected atomic structure is discussed in terms of the contribution of different diffraction orders, considerations of specimen thickness, and optimal adjustment of the microscope objective lens defocus. A similar treatment is also applied to the threefold orientation where micrographs were taken under coherent imaging conditions. For the threefold pattern, fine modulations of the quasicrystalline lattice are obtained which are not observed under less coherent conditions.

The thermal diffusivity of several quasicrystalline and related crystalline alloys was measured both at room temperature and as a function of temperature. It is found remarkably small as compared to conventional metallic alloys. It changes slightly when reversible phase transition takes place and is definitely smaller in the quasicrystalline state than in the corresponding “approximant” state.

The effects of solute-related defects in AICo are measured by changes that they produce in lattice parameter, specific gravity, and elastic moduli. By comparison with the effects of off-stoichiometry on the same parameters in binary Al-Co alloys, the solute-produced defects can be partially characterized. Cell occupancy numbers are calculated and used to infer that vacancies are formed on both sides of stoichiometry and also when solute replaces Al or Co in AICo. These data are also essential to testing the effects of the solutes studied—Mn, Re, and Ti—on mechanical hardening, to be reported separately in Part II.

Solid solution hardening effects are reported for Al-Co-based binary and ternary alloys as a function of off-stoichiometry and of the substitution of the solutes Mn and Re for Co, and of Ti, for Al. Microhardness and stepped flow stress are reported as a function of temperature. Hardening is of the magnitude expected to be caused by conventional elastic interactions between point defects and moving dislocations. For binary alloys the strengths of the interactions are in the proper relative strengths, but not for ternary alloys. In ternary alloys the effects of multiple types of defects are superimposed, but not yet adequately characterized.

Mechanical properties of TiAl base alloys were studied with three-point bending tests in vacuum, air, and gaseous hydrogen. The TiAl-Mn and TiAl (50:50) alloys homogenized at 1273 K exhibited relatively good bend ductility (about 2.5–3.0%) in vacuum, and poor ductility (about 1%) in air and hydrogen. The Ti-rich and Al-rich TiAl alloys, which exhibited little ductility even in vacuum, hardly showed any environmental effect on ductility. These facts may suggest that the mechanical properties of TiAl base alloys are affected at room temperature by the laboratory air and hydrogen, and that plastic deformation plays an important role in environmental embrittlement of TiAl base alloys at room temperature.

A Ni-Cr based hardfacing alloy has been plasma sprayed in ambient and low pressure atmospheres onto mild steel substrates. These coatings exhibit excellent wear and corrosion resistance; however, the significance of microstructure on properties has not been reported. This study relates the structure of the sprayed coatings to the processing conditions. X-ray diffraction results indicate phase separation in air plasma sprayed deposits, while low pressure plasma sprayed deposits exhibit a single supersaturated solid solution. Annealing of the air plasma sprayed coating shows dissolution of the bcc chromium phase, confirming its metastable nature. These results were confirmed using Extended X-ray Absorption Fine Structure (EXAFS) analysis, which further suggests a highly disordered structure, with partial oxidation of selected alloying elements, such as chromium. Transmission electron microscopy indicates a wide variety of microstructures in the air plasma sprayed deposit. In the case of low pressure sprayed deposit, the microstructures are homogeneous and uniform.

Ultramicrotomy was successfully implemented for sectioning solder/Cu and composite solder/Cu samples for TEM. Solder/Cu joints, approximately 10 mm by 2 mm by 3 mm, were carbon coated and dipped in cyanoacrylate ester before being embedded into an epoxy mount. The mounted samples were trimmed in a series of steps to obtain a pyramid-shaped, embedded sample with a flat, trapezoidal face of exposed metal for sectioning. Thin sections were sliced directly from the bulk sample using an ultramicrotome and a diamond knife. Once sectioned, the samples were placed on Formvar and carbon coated copper grids for examination by TEM. Solder/Cu joints made with eutectic (63Sn/37Pb) solder and several composite solders, including Cu, Ni, and Cu6Sn5, were examined. For the first time, it was possible to image simultaneously each phase in the material using a single TEM sample. The various phases present in the solder joints, including the Pb-rich and Sn-rich solder phases, the Cu6Sn5 and Cu3Sn intermetallic phases, and Cu were identified using selected area electron diffraction. Artifacts due to sectioning, such as knife marks, intermetallic tearing, and brittle phase extraction, were observed. These artifacts were minimized by controlling the sectioning conditions.

Lattice parameters, microanalysis, and microstructures of phases present in solution treated and aged samples of Ni-9 at. % Sn and Ni-9 at. % Sn-10 at. % Mo alloys have been investigated. Cellular precipitation was observed to occur in both alloys. During the initial stages of transformation the composition of the α-phase constituting the cells did not change with time. However, on formation of secondary and tertiary cells with interlamellar spacings much higher than those of the primary cells, the tin content of the α-phase of the cell decreased continuously with time and approached the equilibrium composition. The loss of supersaturation in the initial stages increased with decrease in temperature. Almost all of the molybdenum remained in the α-phase which contains 6.7 at. % Sn and 10.3 at. % Mo. Very little molybdenum partitioned to the compound which contained 24.9 at. % Sn and 0.40 at. % Mo. The presence of molybdenum considerably decreased the rate of nucleation and growth, reduced the interlamellar spacing, and increased the loss of supersaturation. However, the increase in hardness was observed to be small which is attributable primarily to solid solution hardening.

A rapid and accurate method of measuring fractal dimension of a fractured surface is described. The method uses a stereo pair of photomicrographs taken in a scanning electron microscope and digitized for computer analysis. The computer can automatically compare the offset at many places in the two images and calculate their height on the basis of the parallax angle. The sum of the area of all planes formed by an array of three-dimensional points is an approximation of the true surface area. The scale can be varied both in the microscope and in the computer; therefore, a fractal dimension can be calculated. Unlike previous methods, this one is direct and gave results intermediate between two prior indirect measurements.

The crystallization process of amorphous electrodeposited samples of composition Co100– x P x (10 < x < 25) has been monitored by differential scanning calorimetry (DSC) and the resulting microstructure has been studied by scanning electron microscopy (SEM) and x-ray diffraction (XRD). Samples of composition given by x < 21 crystallize through two consecutive stages, while those with x > 21 crystallize through a single one. Depending on the composition and crystallization stage, activation energies varying from 1.76 to 2.02 eV and frequency factors of the order of 1013–1014 s–1 have been evaluated. The DSC measurements are compatible with the coexistence of two amorphous phases with different compositions in the regions that are located near the edges of the samples. The analysis of the microstructure resulting from crystallization has shown the existence of two different types of texture for samples with values of x respectively above and below 21, as well as the presence of linear structures oriented perpendicular to the plane of the samples. The development of these features can be attributed to the fundamental role that the polarization, due to magnetization, plays in the crystallization process of this system. A gradual variation of the grain size has also been observed, indicating that crystallization takes place by an inhomogeneous nucleation and growth mechanism.

A new method for tensile testing of thin films is presented. The strain is measured directly on the unsupported thin film from the displacement of laser spots diffracted from a thin grating applied to its surface by photolithography. The diffraction grating is two-dimensional, allowing strain measurement both along and transverse to the tensile direction. In principle, Young's modulus, Poisson's ratio, and the yield stress of a thin film can be determined. Cu, Ag, and Ni thin films with strong ⟨111⟩ texture were tested. The measured Young moduli agreed with those measured on bulk crystals, but the measured Poisson ratios were consistently low, most likely due to slight transverse folding of the film that developed during the test. The yield stresses of the evaporated Cu and Ag thin films agreed well with an extrapolation of the Hall-Petch relation found for bulk materials. Ni thin films are known to deviate from a bulk Ni Hall–Petch relation for submicron grain sizes, and sputtered Ni films show much higher yield stresses than electrodeposited or vapor-deposited films of similar grain size. Our sputtered Ni films had higher yield stresses than other sputtered films from the literature.

The carbon deposits on graphite electrodes formed during the electric discharge in a chamber used for fuUerene production contained nanotubules and fullerenes. X-ray and high resolution transmission electron microscopy investigation revealed that the deposits consisted of strongly deformed graphite microblocks. The nanotubules were found at boundaries of microblocks where carbon hexagonal planes were strongly distorted, suggesting that nanotubules were formed during atomic carbon condensation.

25 μm thick Upilex films (registered UBE trademark) were carbonized, then graphitized at various temperatures up to 2800 °C and studied by optical and electron microscopies. While the graphitizing behavior of Kapton films is similar to that of anthracites, Upilex graphitization is erratic from one film to the other. The thickness of the better graphitizing Upilex films decreases as the anisotropy increases. Their graphitization occurs at a relatively low temperature (2100 °C), because the oxygen is entirely labile (no cross-linking). Non-graphitizing films are obtained when oxygen remains stable as the heat-treatment temperature (HTT) increases. They stay optically isotropic and microporous without flattening, and even show a limited swelling instead of a thinning. This behavior is attributed to the random mobility of the imide part of the molecule when carbonization starts.