@article{oai:ir.kagoshima-u.ac.jp:00003225,
 author = {藤井, 孝一 and FUJII, Koichi and 白石, 孝信 and SHIRAISHI, Takanobu},
 journal = {鹿児島大学歯学部紀要},
 month = {Mar},
 note = {Ordering and age-hardening behaviors in Cu_<0.5>Au_<0.5-X>Ni_X alloys (in at%, x=0 ～ 11.9) were investigated by means of electrical resistivity measurement, hardness test, X-ray diffraction and transmission electron microscopy. In addition, corrosion in alloys mentioned above was also evaluated. The effects of Ni contents on ordering and age-hardening behaviors were as follows ; 1 ) For each alloy aged for up to 50000min at 300℃, the maximum value of hardness ranged between 275 and 330 Hv and decreased little by little depending on the increase of Ni contents (at %) . And the aging time when softening started increased slightly in order of alloys CA-1. CAN-2 and -3 and also the softening rate was suppressed by degrees. For the alloys CAN-4 and -5,the softening rate at the overaging stage was very slow. 2 ) Upon aging treatment at 300℃, a single phase with the CuAu I-type superstructure was produced in the alloys CA-1,CAN-2 and -3. On the other hand, in the alloys CAN-4 and -5,a mixture of a CuAu I-type ordered phase and a smail amount of nickel-rich α_2 phase with the face-centered cubic structure was produced. From these results, it can be seen that the hardening would be due to the introduction of coherency strain at the interface between the CuAu I nuclei and the surrounding matrix and that a loss of coherency strain at interface occurred by twinning brought about softening of the alloy, I.e., overaging. Potentiodynamic (-500 to 1000mV) and potentiostatic (750mV, 600s) polarization measurements were conducted in l%NaCl solution (37℃) deaerated with N_2 gas bubbling, using a platinum (a counter electrode) and KCI saturated Ag/AgCl (a reference electrode) . For the Cu_<0.5>Au_<0.5-X>Ni_X alloys tested in the present study, it was found that there was little difference in Q values between the disordered and the ordered alloys and that the Q values would be mainly controlled by the dissolution of Cu from the Cu_<0.5>Au_<0.5-X>Ni_X alloys and Ni was little dissolved.},
 pages = {35--45},
 title = {Cu_<0.5>Au_<0.5-X>Ni_X系合金の相変態過程と時効硬化挙動},
 volume = {13},
 year = {1993}
}