Spray automated balancing of rotors: Methods and materials

The work described consists of two parts. In the first part, a survey is performed to assess the state of the art in rotor balancing technology as it applies to Army gas turbine engines and associated power transmission hardware. The second part evaluates thermal spray processes for balancing weight addition in an automated balancing procedure. The industry survey reveals that: (1) computerized balancing equipment is valuable to reduce errors, improve balance quality, and provide documentation; (2) slow-speed balancing is used exclusively, with no forseeable need for production high-speed balancing; (3) automated procedures are desired; and (4) thermal spray balancing is viewed with cautious optimism whereas laser balancing is viewed with concern for flight propulsion hardware. The FARE method (Fuel/Air Repetitive Explosion) was selected for experimental evaluation of bond strength and fatigue strength. Material combinations tested were tungsten carbide on stainless steel (17-4), Inconel 718 on Inconel 718, and Triballoy 800 on Inconel 718. Bond strengths were entirely adequate for use in balancing. Material combinations have been identified for use in hot and cold sections of an engine, with fatigue strengths equivalent to those for hand-ground materials

Machine tools and fixtures: A compilation

Innovations developed by NASA, AEC, and their contractors concerning tools, adaptors, jigs, and fixtures useful in machining a wide variety of materials are presented

The implementation of nanoimprint lithography for the fabrication of patterned magnetic media

Advances in technology are having profound effects throughout society. This is no truer than in the way information is being stored. The primary form of information storage for at least the past millennium has been paper. Today, an ever increasing amount of information is being stored electronically. An increased demand for high-performance, low-cost information storage has been a major catalyst in increasing the popularity of hard drives. In 2002, two exabytes of original information was stored on hard drives. This is ten times the amount of all printed material in the world if it were converted to electronic files. To keep up with this demand, the capacity of hard drives has increased by at least 60% annually since 1991. The capacity has mainly increased by scaling down the relevant dimensions much in the same way that has been done with microprocessors. Scaling cannot indefinitely be used to increase the capacity of hard drives that employ longitudinal magnetic recording. Before long, the superparamagnetic effect will limit the achievable information capacity of hard drives using conventional recording. Therefore, new technologies will be needed. Perpendicular recording, one of several new technologies, will make its entrance into the market later this year in a hard drive designed by Toshiba for Apple\u27s iPod music player. It is said that the hard drive will have an areal bit density of 133 Gbits/in2. This is an increase of 75% over what is currently available today. However, the hard drive will still employ a continuous magnetic medium. Even greater densities can be achieved if the magnetic medium is physically patterned into isolated bits. This technology, known as patterned magnetic media, has the potential of achieving areal bit densities greater than 1 Tbit/in2. The challenge is finding a way to fabricate it. A high-throughput, low-cost pattern generation technology is needed. Research completed with nanoimprint lithography demonstrates that it can be used to fabricate patterned magnetic media. Several patterns of magnetic media were fabricated with densely packed sub-20-nm features that would produce an areal bit density of at least 258 Gbits/in2

JTEC Panel report on electronic manufacturing and packaging in Japan

This report summarizes the status of electronic manufacturing and packaging technology in Japan in comparison to that in the United States, and its impact on competition in electronic manufacturing in general. In addition to electronic manufacturing technologies, the report covers technology and manufacturing infrastructure, electronics manufacturing and assembly, quality assurance and reliability in the Japanese electronics industry, and successful product realization strategies. The panel found that Japan leads the United States in almost every electronics packaging technology. Japan clearly has achieved a strategic advantage in electronics production and process technologies. Panel members believe that Japanese competitors could be leading U.S. firms by as much as a decade in some electronics process technologies

Development of Automotive Handheld Tool

In the automotive repair industry doors are being stripped every day to be repainted. Insurance appraisers will pay for up to one hour for removal and installing door moldings. The process includes removing leftover adhesive tape and re-taping for installation. The current industry practice is timely and aggravating for technicians. The goal of this project is to develop a tool that removes double-sided adhesive tape from door moldings in a timely fashion. An objective was to model a device to fit the constraints of the tools operating path. A second objective was to explore different angles for our blade to see its effects on adhesive removal. An analysis of the design and its several iterations, along with fabrication details are discussed in this report

Index to 1981 NASA Tech Briefs, volume 6, numbers 1-4

Short announcements of new technology derived from the R&D activities of NASA are presented. These briefs emphasize information considered likely to be transferrable across industrial, regional, or disciplinary lines and are issued to encourage commercial application. This index for 1981 Tech Briefs contains abstracts and four indexes: subject, personal author, originating center, and Tech Brief Number. The following areas are covered: electronic components and circuits, electronic systems, physical sciences, materials, life sciences, mechanics, machinery, fabrication technology, and mathematics and information sciences

A NEW PIEZOELECTRIC MICROACTUATOR WITH TRANSVERSE AND LATERAL CONTROL OF HEAD POSITIONING SYSTEMS FOR HIGH DENSITY HARD DISK DRIVES

In high density magnetic hard disk drives, both fast track seeking and extremely accurate positioning of the read/write head are required. A new piezoelectric microactuator with transverse and lateral control of the head positioning system for high density hard disk drives is proposed. First, the structure of the new piezoelectric microactuator is illustrated. Design of the new microactuator is based on the axial deformation of piezoelectric elements for lateral motion and the bimorph actuation of piezoelectric elements for transverse motion. Next, a mathematical model of the microactuator system is defined. Static properties associated with the displacement of the system are evaluated and then dynamic system equations of the system are evaluated. Frequency response of the system is studied based on the dynamic system equations of the actuator system. Dynamic properties of the system with a variety of system parameters are evaluated. Finally, the controller design for the actuator is presented. Simulation results show that the new actuator achieves a maximum stroke of displacement of more than 0.2m with servo bandwidth of more than 5 kHz in the lateral direction and the flying height is decreased to less than 6 nm with resonance frequency of more than 100 kHz under the 0.5 % damping assumption. The new piezoelectric microactuator improves performance of high density hard disk drives by increasing servo bandwidth and decreasing flying height

Technology 2000, volume 1

The purpose of the conference was to increase awareness of existing NASA developed technologies that are available for immediate use in the development of new products and processes, and to lay the groundwork for the effective utilization of emerging technologies. There were sessions on the following: Computer technology and software engineering; Human factors engineering and life sciences; Information and data management; Material sciences; Manufacturing and fabrication technology; Power, energy, and control systems; Robotics; Sensors and measurement technology; Artificial intelligence; Environmental technology; Optics and communications; and Superconductivity

Beam lead technology

Beam lead technology for microcircuit interconnections with applications to metallization, passivation, and bondin

Numerical evaluation and analysis of the adhesion phenomena in thermal barrier coating systems through bio-mimicking plasma process

Thermal Barrier Coatings or TBCs when abbreviated are an imperative part of the thermal protection system of expensive equipment and machinery in the automobile and aeronautics industry. They provide protection to expensive alloy materials upto a temperature of 2700° C without expensive metallurgical additions. Unfortunately, the problem of coating adhesion has plagued the TBC field for years, leading to catastrophic failures in critical TBC systems. Efforts to chemically improve bond strength has not been entirely successful, so the only other efficient way to do this would be some kind of mechanical interlocking that occurs at micro/nano scales. This research work deals with the improvement of adhesion in TBC systems by numerical simulation and bench-marking of micro-geometric surface features that has been synthesized or reproduced in laboratory environment through electrochemical operations. For this, several geometries that benefit mechanical interlocking, and consequently improvements in mechanical \u27adhesion\u27 in TBCs has been compared. To simulate the mechanical and thermal loading on the micro geometries and to observe their effect, the commercial finite element software COMSOL was used. An analogy was drawn between the biological, Van der Waals dry adhesion mechanism in Gecko feet and that in the top surface of the thermally grown oxide (TGO) layer in TBC whereas the \u27mushroom head geometry\u27 in the Gecko feet provides improved adhesion (as much as 10 folds) compared to other geometries (spatular head, spherical head, or plain triangular crevices). An affordable synthesis process, termed “Electrolytic Plasma Processing (EPP) for recreating this specific geometry, is also proposed and its utility briefly entertained. The work ends with recommendations and suggestions for future works on this topic