Properties of Fe-Zr-N Thin Films
Gases emerging from Fe-Zr-N films with various compositions during heating were analyzed by thermal desorption spectroscopy. The structures and magnetic properties of films were also investigated. H2, N2 and Ar were detected at 300-400°C, 500°C and 650°C, respectively. Larger amounts of N2 were emitted by films which contained larger amounts of N2. The changes in composition of films due to the emerging N2 is as follows. The composition changed for N/Zr ratios ranging from N/Zr≫1 to N/Zr~1, but was unchanged when N/Zr1. A (100) preferred orientation occurred in films in which the composition was N~Zr≫8 at% in the as-deposited state, while either a (100) orientation or random orientation occurred in all other cases. Under the former conditions, Fe-Zr-N films showed excellent soft magnetic properties and thermal stability up to 700°C.
Fe-N スパッタ薄膜における Zr,Ti 添加の効果
The effects of addition of Zr and Ti on iron films containing nitrogen were investigated. The structures and magnetic properties were studied as a function of the contents of Zr and Ti. The coercive force of Fe-N films increased sharply after being annealed at about 350°C, while Fe-Zr-N and Fe-Ti-N films showed small coercive force after annealed at higher temperature. The addition of Zr and Ti in small amounts was highly effective in improving the thermal stability of Fe-N because it prevented the grain growth of iron.
Experimental study on bond behavior between high-strength grout and deformed steel bars
Abstract Engineers use high-strength grout to connect precast concrete members for its low shrinkage and good fluidity. This paper designed 87 central pull-out specimens using the control variable method to investigate the influence of factors on the rebar-grout bond property such as compressive strength, steel grade, bar diameter, transverse stirrups, and bond length. The test result showed that improving grout compressive strength (85.8 MPa–122.7 MPa) cannot improve the bond strength, which was different from the previous conclusions of concrete pull-out tests. Simplified formulas were presented for calculating the characteristic values of bond strength, residual strength, peak slip, and relative slip of load-holding platform based on parameter analysis. Then, a constitutive model was proposed to predict the full-range bond stress-slip curve of high-strength grout and steel bar specimens from bearing to failure. Finally, FEA models were established to evaluate the applicability and accuracy of the constitutive model.