Engineering Applications and Devices: Poster Session
Program Organizers: Alan Pelton, G.RAU Inc.

Monday 5:30 PM
July 10, 2017
Room: Crystal Ballroom A
Location: Hyatt Regency Chicago

P1-15: A Proposal Experimental Stress Analysis Method based on Stress-Induced-Martensite-Transformation in Single-crystalline SMA: Jacinto Cortés Pérez1; Salvador Cabrera González1; Fernando García Castillo2; Alberto Reyes Solís1; Horacio Flores Zuñiga3; Vicente Amigó Borras4; 1Universidad Nacional Autónoma de México; 2Tecnológico de Estudios Superiores de Chalco; 3Instituto Potosino de Investigación Científica y Tecnológica; 4Universidad Politécnica de Valencia
     An experimental stress analysis technique based in a mathematical model of plane stress induced martensitic transformation is present. The mathematical model used predict for a single crystal sample the mark on the observation surface associate to each one martensitic variants etc., knowing: a) crystalline orientation of the sample, b) Transformation system, c) the shear magnitude and c) Characteristic parameters such as: transformation temperatures, stress ratio and the stress state. On the other hand, the mathematical model used here is capable to make the inverse processes.Based on the last in present job we show two application cases found in industrial application: Compression and buckling in a column and Torsion on a screw. The results allow us shows the change of martensitic variant during the bucking in a large column. Also we calculate the mark will appear on the screw head surface and the torsion load which induced it.

P1-16: Damping Characteristics of the Inherent and Intrinsic Internal Friction of Ti50Ni40Pd10 Shape Memory Alloy: Shyi-Kaan Wu1; Yu-Ning Lee1; Bo-Yen Huang2; Shih-Hang Chang2; 1National Taiwan University; 2National Ilan University
    This study investigated the damping properties of the inherent and intrinsic internal friction (IFPT+IFI) of Ti50Ni40Pd10 shape memory alloy (SMA) using a dynamic mechanical analyzer under isothermal conditions. Ti50Ni40Pd10 SMA shows a B2→B19 internal friction peak with tan δ=0.148 at -7 oC and a B19→B19’ peak with tan δ=0.042 at -73 oC in the cooling tan δ curve when measured at a constant cooling rate of 3 oC/min. The tan δ values measured at B2→B19 and B19→B19’internal friction peaks temperatures decrease substantially under isothermal conditions. Ti50Ni40Pd10 SMA exhibited a (IFPT+IFI)B2→B19 peak with tan δ = 0.038 at 3 oC and a (IFPT+IFI)B19→B19’ peak with tan δ = 0.026 at -70 oC. Ti50Ni40Pd10 SMA possesses high (IFPT+IFI) peaks under isothermal conditions; however, their martensitic transformation temperatures are well below room temperature. TiNiPd SMAs are potential candidates for high-damping materials, but further increasing their martensitic transformation temperatures is needed for practical applications.

P1-17: Development of Conductive Yarns using Ni-Ti Coil Spring: Kwang Jee1; WOO JANG2; 1Korea Institute of Science and Technology; 2Chosun university
     Conductive yarns, able to carry electric power and signal, are expected to be indispensible parts for wearable device. The conductive yarns are requested to have elasticity as well as fatigue resistance. Nano particle embedment or metals electroplating on textile is applied, however, degradation easily occurs due to repetitive deformation. In this work, a new conductive yarn with a good endurance is developed using Ni-Ti alloy. Ni-Ti coil spring is wound around elastic textile so that the coil and the textile are deformed and recovered all together. The new yarn shows an excellent endurance and no permanent deformation even after severe deformation such as washing.

P1-18: Foil and Film-based SMA Microactuators for Fluid Handling: Hinnerk Ossmer1; Marcel Gueltig1; Christof Megnin1; Christoph Wessendorf1; Manfred Kohl2; 1memetis; 2Karlsruhe Institute of Technology
     Memetis is a high-tech Startup based in Karlsruhe, Germany, which aims at developing and commercializing film and foil-based shape memory alloy (SMA) microactuators. The project emerged from the extensive research expertise in this field at the Karlsruhe Institute of Technology (KIT). Planar SMA actuators exhibit a number of specific advantages (compared to wires) including compactness and fast response times due to their high surface-to-volume ratio. Furthermore, complex actuator shapes having several degrees of freedom and different actuation modes (like tension, bending and rotation) may be realized in a single element.Here, we present microfluidic devices such as microvalves, which are fabricated from cold-rolled, 20 - 100µm thick NiTi-based foils micromachined by laser cutting. In addition, new fatigue-free TiNiCu alloy films produced by magnetron sputter-deposition are explored for microactuation applications. Rapid prototyping and manufacturing techniques such as CNC milling and 3D printing of polymer housings are combined for customer-specific device development.

P1-19: Inherent and Intrinsic Internal Friction of Cu-28Zn-3.5Al Shape Memory Alloy Measured under Isothermal Conditions: Wei-Jyun Chan1; Shyi-Kaan Wu2; Yu-Ning Lee2; Shih-Hang Chang1; 1National Ilan University; 2National Taiwan University
     This study investigated the inherent and intrinsic internal friction of Cu-28Zn-3.5Al shape memory alloy (SMA) under isothermal conditions using a dynamic mechanical analyzer. Cu-28Zn-3.5Al SMA exhibited a B2→18R internal friction peak at approximately -23 oC with a tan δ value of 0.232. However, the damping capacity of the internal friction peak decreased significantly under isothermal condition. The tan δ value of the inherent and intrinsic internal friction peak (IFPT+IFI)B2→18R for Cu-28Zn-3.5Al SMA is determined as 0.050, which is much higher than those of Ti50Ni50, Ti50Ni40Cu10, Ni2MnGa, and Cu-Al-Ni SMAs reported before. Consequently, Cu-28Zn-3.5Al SMA is a potential high-damping material for use at a steady temperature. Nevertheless, the low martensitic transformation temperature (-2.5 oC) may restrict its practical application.Keywords: shape memory alloy; martensitic transformation; internal friction; dynamic mechanical analysis

P1-20: Relationship between Applied Stress and Hydrogen-related Fracture Behavior in Martensitic Steel: Yasunari Takeda1; Takashi Yonemura1; Yuji Momotani1; Akinobu Shibata1; Nobuhiro Tsuji1; 1Kyoto university
    Hydrogen embrittlement is one of the serious issues for practical use of high strength martensitic steels. There are mainly two modes of hydrogen-related fracture in martensitic steel; one is intergranular fracture at prior austenite grain boundaries, and the other is quasi-cleavage fracture inside prior austenite grains. For understanding the underlying mechanism of hydrogen embrittlement, it is important to elucidate the distinct condition that decides whether quasi-cleavage fracture or intergranular fracture occurs. The present study investigated the relationship between applied stress and fracture mode of hydrogen embrittlement in 8Ni-0.1C martensitic steel. Hydrogen embrittlement properties were evaluated by constant load tests. Hydrogen was introduced into the specimens by electrochemical charging in a 3 % NaCl and 3 g L-1 NH4SCN aqueous solution before and during constant load tests. In the presentation, we will discuss the mechanism of quasi-cleavage fracture and intergranular fracture from the view point of applied stress.

P1-21: Shape Memory Actuator Inside a Clutch. Material Characterization by Thermal Cycling under Load: Ignacio Corro1; V. E. Araujo1; Juan Beiroa1; Rosana Gastien1; 1CITEDEF
     CuAlNi shape memory alloys have low diffusion at temperatures higher than room temperature, this property gives them the possibility of being used in high temperature applications. For example, an interesting application is a security clutch that avoids overheating of the lubricant in transmissions. The actuator element of the clutch is a shape memory alloy that senses lubricant temperature. If this temperature reaches some critical value, the shape memory element acts opening the clutch. A device to characterize thermally induced martensitic transformation under an applied load for shape memory alloys (SMA) is presented. This device can be used in any testing machine and allows recording elongation vs temperature in order to obtain parameters such as critical temperatures, thermal hysteresis of the martensitic transformation and repeatability of the cycle. This test simulates satisfactorily conditions in service of the actuator inside the clutch.

P1-22: Research Combing Experiment and FEM Analysis on Sliding Wear Behaviors and Mechanism of TiNi Alloy: renbo xu1; Weiwei Jin1; 1Wuhan University of Science and Technology
    The sliding wear behaviors of TiNi alloy with different phase were studied in this paper. It was demonstrated that wear resistance of austenite phase TiNi alloy was best. The wear mechanism of TiNi alloy and factors affect its wear resistance were discussed. It was observed wear mechanism of TiNi alloy during sliding is adhesive at low load and abrasive under high load, and stress induced martensitic transformation occurred. Based on experiment results, it can be considered that high wear resistance of TiNi alloy greatly benefits from pseudoelasticity. A finite element analysis was conducted to simulate contact behaviors of TiNi alloy during sliding. The results indicate that pseudoelasticity of TiNi alloy can effectively enhance elastic contact area and critical stress for plastic deformation, thus diminish plastic damage during sliding. Both results of experiment and finite element analysis demonstrated that pseudoelasticity is greatest beneficial factor to high wear resistance of TiNi alloy.