Quasistatic and dynamic mechanical properties of Al–Si–Cu structural films in uniaxial tension

Abstract

In this article, the quasistatic and dynamic tensile properties of aluminum-silicon-copper (Al-Si-Cu) alloy films are described. The films were deposited by sputtering onto thermally oxidized Si wafers, and then half of the wafers were heat treated at 623 K in nitrogen gas for 1 h. Specially developed environment-controlled uniaxial tensile test equipment was used to carry out the quasistatic tensile test, stress relaxation test, and cyclic loading test at temperatures ranging from room temperature (RT) to 573 K in high vacuum, and the influence of annealing on the mechanical characteristics was investigated. The Young's modulus did not show annealing dependency. The mean value was 65 GPa at RT, and gradually decreased with increasing test temperature. The yield stresses of nonannealed and annealed films were 168.5 and 129.6 MPa, respectively, which also decreased with temperature rise. In stress relaxation test results, creep exponents in respective films were obtained from curve fitting using the Norton law, which indicated that creep deformation was restricted by annealing. The cyclic loading test was performed under stress-and displacement-amplitude-constant modes. The stress-amplitudeconstant mode test provided creep deformation acceleration to failure, whereas the displacementamplitude-constant mode test showed a gradual drop of stress amplitude. The stress-amplitude change was compared with stress relaxation curves; consequently, the creep deformation was dominant to the degradation of Al-Si-Cu films subjected to cycling loading with constant displacement amplitude.

Mechanical reliability of FIB-fabricated WC–Co cemented carbide nanowires evaluated by MEMS tensile testing

“…By using electrostatic actuator or thermal actuator, tension force can be applied to Si NWs [2][3][4], C NWs [5,6], and other metallic, semiconductor, and insulator NWs [7,8]. For the micron-sized specimens like sputtered films, many types of tensile test techniques have been developed so far [9][10][11][12][13][14][15][16][17][18][19]. We have several types of mechanical testing techniques for thin films and NWs [3,4,[9][10][11][20][21][22][23].…”

“…For the micron-sized specimens like sputtered films, many types of tensile test techniques have been developed so far [9][10][11][12][13][14][15][16][17][18][19]. We have several types of mechanical testing techniques for thin films and NWs [3,4,[9][10][11][20][21][22][23]. By adopting them to evaluating size effect phenomena within the nano-millimeter size range, investigating the limit size showing its excellent mechanical characteristics is of significance, for realization of future strong MEMS components made of hard metals.…”

Mechanical Reliability of Reactively Alloyed NiAl as a Structural Material

“…The SCS frame is composed of four SCS springs, two hooking holes, and a through hole in the specimen section. (12)(13)(14) Then, an Al/Ni multilayer film sheet is attached onto the specimen section with glue. An in-house ternary-source direct current (dc) magnetron sputtering equipment is used for the deposition of the Al/Ni multilayer film.…”

“…The details of the equipment are published elsewhere. (13,(16)(17)(18)(19) The equipment consists of a piezoelectric actuator, an actuator case with a lever for elongation amplification, a load cell with a resolution of 2 mN, a linear variable differential transformer (LVDT) for tension stroke measurement, an image analysis system with a charge-coupled device (CCD) camera for the specimen's displacement measurement, and a specimen holder with a microheater. The image analysis system has a resolution of 13 nm/pixel for the displacement measurement.…”

Effect of Vacuum Annealing on Tensile Mechanical Characteristics of Au Bonding Wires

“…The Si frame fabricated by deep reactive ion etching (DRIE) is composed mainly of two square holes in the fixed and movable parts and four Si springs supporting the movable part. (9)(10)(11) The alignment jig has two square convex structures with a slit, measuring 0.05 mm in width and 1.4 mm in depth, fabricated by wire discharge. The convex structures were put through two square holes of the Si frame before setting the Au bonding wire.…”