Embedded Files
黃家聖 (Chia-Sheng Huang)
黃家聖 (Chia-Sheng Huang)
Investigation on Coefficient of Thermal Expansion and Fatigue Properties of Electroplated Ni-diamond Nanocomposite
Investigation on Coefficient of Thermal Expansion and Fatigue Properties of Electroplated Ni-diamond Nanocomposite
電鍍鎳-鑽奈米複合材料之熱膨脹係數及疲勞特性研究
電鍍鎳-鑽奈米複合材料之熱膨脹係數及疲勞特性研究
Electroplated Ni is the common structure material in MEMS devices. Recently, the nanotechnology has advanced it for enhanced material properties and wide applications by incorporated nano-particles. In this dissertation, the electroplated Ni-diamond nanocomposite has been investigated thoroughly in terms of CTE variation mechanism, material application, and reliability issue.
Electroplated Ni is the common structure material in MEMS devices. Recently, the nanotechnology has advanced it for enhanced material properties and wide applications by incorporated nano-particles. In this dissertation, the electroplated Ni-diamond nanocomposite has been investigated thoroughly in terms of CTE variation mechanism, material application, and reliability issue.
For the CTE variation mechanism, through the XRD investigation, residual stress types of Ni-based nanocomposites can be determined. These residual stresses resulted from co-deposited process are thought as the promising factor to affect the CTE variations. According to measurement results, the incorporated nano-diamond particles in Ni matrix will enhance the CTE of electroplated Ni from 23 to 50.1 ×10-6/℃ with residual compressive stress; oppositely, the incorporated nano-SiO2 particles in Ni matrix will diminish the CTE of electroplated Ni from 23 to 18 ×10-6/℃ with residual tensile stress.
For the CTE variation mechanism, through the XRD investigation, residual stress types of Ni-based nanocomposites can be determined. These residual stresses resulted from co-deposited process are thought as the promising factor to affect the CTE variations. According to measurement results, the incorporated nano-diamond particles in Ni matrix will enhance the CTE of electroplated Ni from 23 to 50.1 ×10-6/℃ with residual compressive stress; oppositely, the incorporated nano-SiO2 particles in Ni matrix will diminish the CTE of electroplated Ni from 23 to 18 ×10-6/℃ with residual tensile stress.
For the material application, the CTE property of Ni-diamond nanocomposite is applied on a newly Ni-based thermal bimaterial structure by bimorph effect. Thermal bimaterial structure made of electroplated Ni/Ni-diamond nanocomposite can achieve upward and downward out-of-plane displacement easily by controlling the plating sequence of electroplated Ni and Ni-diamond nanocomposite. Since Ni and Ni-diamond nanocomposite have different CTE but similar crystal structure and process temperature, the fabricated thermal bimaterial structures show better interfacial bonding strength and smaller residual thermal stress.
For the material application, the CTE property of Ni-diamond nanocomposite is applied on a newly Ni-based thermal bimaterial structure by bimorph effect. Thermal bimaterial structure made of electroplated Ni/Ni-diamond nanocomposite can achieve upward and downward out-of-plane displacement easily by controlling the plating sequence of electroplated Ni and Ni-diamond nanocomposite. Since Ni and Ni-diamond nanocomposite have different CTE but similar crystal structure and process temperature, the fabricated thermal bimaterial structures show better interfacial bonding strength and smaller residual thermal stress.
For the reliability issue, the characterizations of fatigue and Young’s modulus have been studied employing the bending-test method on the specimens made of electroplated Ni and Ni-diamond nanocomposites. According to the measurement results, Ni-diamond nanocomposite has slightly smaller fatigue strength than that of pure electroplated Ni due to the ductility reduction resulted by the nanoparticles. However, once the particle size of nano-diamond is reduced from 350 to 50 nm, it has been found that the electroplated Ni-diamond nanocomposite can have higher Young’s modulus (~13.6% enhancement) and comparable fatigue strength (~2.4 GPa) with that of pure electroplated Ni.
For the reliability issue, the characterizations of fatigue and Young’s modulus have been studied employing the bending-test method on the specimens made of electroplated Ni and Ni-diamond nanocomposites. According to the measurement results, Ni-diamond nanocomposite has slightly smaller fatigue strength than that of pure electroplated Ni due to the ductility reduction resulted by the nanoparticles. However, once the particle size of nano-diamond is reduced from 350 to 50 nm, it has been found that the electroplated Ni-diamond nanocomposite can have higher Young’s modulus (~13.6% enhancement) and comparable fatigue strength (~2.4 GPa) with that of pure electroplated Ni.
[1] C.-S. Huang, J. Chung, Y.-T. Cheng and W. Hsu (January 2007). Thermal Bimetallic Microactuators by Ni and Ni-diamond Nanocomposite, The 2nd Annual IEEE International Conference on Nano/Micro Engineered and Molecular Systems, Bangkok, Thailand.
[2] C.-S. Huang, Y.-T. Cheng, C.-J. Yeh, H.-K. Liu, and W. Hsu (June 2009). Young’s modulus and fatigue lifetime improvements by diamond size effect on electroplated Ni-diamond nanocomposite, The 15th International Conference on Solid-State Sensors, Actuators and Microsystems, Denver, U.S.A..
[2] C.-S. Huang, Y.-T. Cheng, C.-J. Yeh, H.-K. Liu, and W. Hsu (June 2009). Young’s modulus and fatigue lifetime improvements by diamond size effect on electroplated Ni-diamond nanocomposite, The 15th International Conference on Solid-State Sensors, Actuators and Microsystems, Denver, U.S.A..
[3] C.-S. Huang, Y.-T. Cheng, J. Chung and W. Hsu, 2009, "Investigation of Ni-based Thermal Bimaterial Structure for Sensor and Actuator Application." Sensors and Actuators :A 2009, 149, 298-304.
Page updated
Google Sites
Report abuse