22. Hahin, Ranier; Schulze, Peter. Effective applications of ultrasonic machining of glass and ceramics, American Ceramic Society Bulletin. 1993 Aug; 72(8): 102-106. Machining of ceramics is a continuing challenge. Ultrasonic energy is a promising approach to shaping complex ceramic components in small-volume production. 9 Refs. 23. Obikawa, Toshiyuki; Sasahara, Hiroyuki; Shirakashi, Takahiro; Usui, Eiji. Effects of non-Ilnearity of dynamic
cutting process upon self-excited chatter vibration (3rd report) shear localized chip formation realizing finite amplitude chatter vibration. Journal of the Japan Society for Precision Engineering. 1993 Jul; 59(7): 1151-1156. Finite amplitude chatter vibration can be attributed to the non-linearity of cutting processes and machine tools. In this paper, it is found that just above the stability limit a new non-linear mechanism of cutting process, i.e., shear localized chip formation realizes finite amplitude chatter vibration. This is because shear localized chip formation reduces the input energy to vibration system from cutting process before the tool comes out of work or the tool flank face collides the machined surfaces. Thus shear localized chip formation is predicted by energy approach for the analysis of finite amplitude chatter vibration. A criterion for the beginning of the localized shear is determined by the cutting experiment with the tools of large negative rake angle and at constant undeformed chip thickness. Cutting force variations and shape of shear-localized chip calculated for the dynamic cutting process in wave removal sufficiently agree with experimental results. 9 Refs. 24. Pischow, Kaj A.; Korhonen, Antti S. Effects of voltage pulses on precipitates during scanning tunneling microscopy studies. Materials Characterization. 1993 Sep; 31(2): 77-81. The effects of short 1-ms voltage pulses of 5 V on the precipitates on an electropolished and etched surface of a micro-alloyed steel have been studied. Such pulses are commonly used for tip cleaning during scanning tunneling microscopy. It is proposed that the voltage pulses can be used as a new type of analytical tool in studying the characteristic features of precipitates. 13 Refs. 25. Pliska, P.; Lukosz, W. Electrostatically actuated Integrated optical nanomechantcal devices. SPIE Integrated Optics and Microstructures; 1992 Sep 8; Boston, MA. Bellingham, WA: International Society for Opticat Engineering; 1993: 259-72. The authors demonstrated that IO nanomechanical devices can be actuated by electrostatic forces. In particular, they investigated the intensity modulation, the deflection, and the (de-)focusing of guided waves by electrostatically actuated effective-refractive-index-shifting elements E. The nanomechanical intensity modulator worked at modulation frequencies up to several hundreds of kHz. Much higher frequencies could be realized by reducing the time constant of the capacitors and by miniaturizing of the bridges or cantilevers used as elements E. The authors exped that by miniaturization of the effective-refractive-index-shifting elements, also the drive voltages required for their electrostatic actuation can be reduced to a few volts. 26. Miller, A. C. Jr; Stuhlinger, T. W. Evaluation of a scanning Hartmann device for single point turning applications, SPIE - Annual Meeting. Oak Ridge National Lab., TN 1993. 11 pages. This paper concerns a new, machine mounted aspheric metrology device designed to measure a broad range of figures without the use of auxiliary optics. A prototype device, based on the classical Hartmann test, called a Hartmann Optical Surface Tester (HOST) was evaluated on a single point diamond turning machines. Design, initial testing, and validation data from reference spheres, and two types of aspheres will be discussed. Results of a simulation model for estimating acceptable alignment errors for the HOST on the diamond turning machine will also be presented. Peak-to-valley measurement uncertainty on the test optics was found to be better than 0.08 p.m. 27. Phillips, H. M.; Sauerbrey, R. A. Excimer-laser-produced nanostructures in polymers. Optical Engineering. 1993 Oct; The ability of excimer lasers to modify the surface morphology and the electrical conductivity of polymers with spatial resolution on a nanometer scale has been demonstrated. Using holographic techniques with a KrF excimer laser periodic line structures with periods ranging from t66 to 950 nm have been ablated into polyimide (Kapton) and polybenzimidazole (PBI). The nonlinear nature of laser ablation allows linewidths as small as 30 nm to be obtained, exceeding the resolution expected from linear optics. These experiments establish a new spatial resolution limit for laser ablation and illustrate the dependence of resolution on material properties. This technique has been combined with the ability to modify the electrical conductivity of polymers to produce an array of permanently electrically conducting wires in polyimide with a 0.5 I~m width and a 0.9 I~m period. The electrical conductivity of these subrnicrometer wires was greater than 1 ~-lcm ~ 28. Masuda, H.; Nishio, K.; Baba, N. Fabrication of a one-dimensional mlcrohole array by anodlc oxidation of aluminum. Applied Physics Letters. 1993 Dec 6; A one-dimensional microhole array with high-aspect ratio was successfully obtained using anodic oxidation of an aluminum oxide / aluminum / glass structure. This process allows the fabrication of an array of microholes less than 1000 AA diameter without any exposure mask or resist, and the size of the array can be controlled on the basis of the relationship between the thickness of the aluminum layer and anodizing voltage. 29. Blaedel, K. L. Fabrication Technology, Lawrence Livermore National Lab., CA 1993 Mar; UCRL-ID-112774. 9 pages. The mission of the Fabrication Technology thrust area is to have an adequate base of manufacturing technology, not necessarily resident at Lawrence Livermore National Laboratory (LLNL), to conduct the future business of LLNL. The specific goals continue to be to (1) develop an understanding of fundamental fabrication processes; (2) construct general purpose process models that will have wide applicability; (3) document findings and models in journals; (4) transfer technology to LLNL programs, industry, and colleagues; and (5) develop continuing relationships with the industrial and academic communities to advance the collective understanding of fabrication processes. The strategy to ensure success is changing. For technologies in which they are expert and which will continuP to be of future importance to LLNL, they can often attract outside resources both to maintain their expertise by applying it to a specific problem and to help fund further development, A popular vehicle to fund such work is the Cooperative Research and Development Agreement with industry, For technologies needing