High-Temperature Microsample Testing System

ABSTRACT: A better understanding of the thermo-mechanical response, characteristics and properties of materials can lead to improved device performance as well as facilitate the design of new devices and materials for various applications. Although there has been significant progress in the development of micro/nanomechanical testing techniques and tools over the last decade, commercially available tools do not provide adequate capabilities for investigating thermo-mechanical behaviors of micro/nano scale samples at elevated temperatures over 600°C. In order to extend quantitative thermo-mechanical property measurements to higher temperature applications, we propose the development of a high-temperature microsample testing system capable of temperature control up to 1100°C. The proposed thermo-mechanical testing system can perform uniaxial compression and tensile tests inside a scanning electron microscope or under a high-resolution optical microscope and record real-time in-situ video images of the material deformation behavior. In this SBIR we will develop a heating stage capable of sample heating up to 1100°C, a transducer capable of applying a maximum force higher than 5 N and a maximum travel range of 0.5 mm, a sample holder capable of mounting a microsample for tensile test, and a piezo-motor stage for sample approach, alignment, and precise positioning. Successful completion of this SBIR development will provide a high-temperature microsample testing system offering unprecedented capabilities for exploring relationships between temperature, mechanical properties, and structural behavior of materials. BENEFIT: The proposed system is intended for pioneering studies of the thermo-mechanical characteristics of microscale samples at high temperatures up to 1100°C. The realization of the proposed high-temperature microsample testing system will provide an unprecedented thermo-mechanical testing tool to researchers interested in the quantitative exploration of the relationship between temperature, mechanical property, and structural behavior of materials. Many materials and devices are used and operated at high temperatures. The thermo-mechanical reliability and performance of these materials need to be fully understood through proper mechanical testing. Increasing the temperature control capability of the mechanical testing system to cover the sample material/device operating temperature range is critical. Material reliability data related to wear, fatigue, and material strength obtained from thermo-mechanical testing can be used to estimate the possible operational temperature range and life span in the high temperature environment. The proposed mechanical test system will introduce many new scientific findings especially to researchers interested in high temperature materials such as metal alloys, composites, and ceramics routinely used at temperatures from 600°C to 1100°C. The proposed system is compatible with in-situ optical/electron microscopy which can be used to investigate structure-property correlations and the influence of pre-existing defects on the mechanical response of materials. In addition to optical and electron imaging, additional in-situ measurement techniques (e.g. electron backscattered diffraction (EBSD)) can also be employed during the high temperature mechanical test. Performing in-situ microscopy coupled with quantitative micro/nano-mechanical testing can provide a clear differentiation between the many possible causes of force or displacement transients which may include dislocation burst, phase transformation, shear banding or fracture onset. Understanding the fundamentals of micro/nano mechanics can facilitate the design of new devices for various applications and improve overall device performance. The SBIR company"s (our) product user groups have expressed considerable interest in in-situ microscopy micro/nano-mechanical testing capabilities at elevated temperatures. From our experience as a pioneer in the development and commercialization of in-situ electron microscopy micro/nano-mechanical testers, material research laboratories such as university labs, government research institutions, and industrial R & D facilities are the potential customers of the proposed instrument. Based on the feedback from the users, we are confident that the proposed thermo-mechanical testing system can be marketed to many frontier researchers eager to perform unprecedented thermo-mechanical characterizations. Strong demand for the proposed instrument will be derived from researchers and industries whose applications are in advanced alloys, various composite materials, and ceramics. Defense, energy, aerospace, automobile, semiconductor, and composites related industries and research institutions have a high degree of interest in thermo-mechanical tests at elevated temperatures above 600°C. Measuring mechanical properties and investigating material behaviors at high temperatures can help to understand phase transformation behavior, failure mode, and reliability of the structures. This capability can have a tremendous economic impact as it provides a means for tailoring materials for an intended purpose based on their properties. Micro/nano scale material synthesis for enhanced mechanical properties at high temperature will result in more reliable high temperature materials for our country"s benefit.