Subjects: Materials Science >> Materials Science (General) submitted time 2023-03-31 Cooperative journals: 《材料研究学报》
Abstract: A series of micro-arc oxidation (MAO) films were prepared on Mg-Mn-RE alloy by an alternating current with symmetric voltage in different alkaline solutions containing aluminate, phosphate or silicate and then the MAO films were characterized by SEM and XRD. The corrosion resistance of MAO films was evaluated by EIS potentiodynamic polarization. The results indicated that the MAO films prepared in phosphate or silicate systems have low thickness with obvious cracks, leading to poor corrosion resistance. In the contrast, the MAO films prepared in aluminate system exhibit the better corrosion resistance due to the compactness and higher surface quality, which shows a good prospect for the application.
Subjects: Materials Science >> Materials Science (General) submitted time 2023-03-31 Cooperative journals: 《材料研究学报》
Abstract: The influence of C content on the glass forming ability, thermal stability and corrosion resistance of Ni68.6Cr8.7Nb3P(16.5-x)B3.2Cx (x=0, 0.1, 0.3, 0.5, 0.7, 1, %) alloy was studied. The results show that an amorphous rod of 2 mm in diameter could be made for the alloy with 0.5 % C; a certain among of C addition can improve the thermal stability of the Ni- based amorphous alloy; with the increase of C amount, the corrosion resistance of amorphous ribbon in 1 mol/L H2SO4 solution is enhanced gradually.
Subjects: Materials Science >> Materials Science (General) submitted time 2023-03-18 Cooperative journals: 《材料研究学报》
Abstract: The spinel cobalt chromium zinc ferrites (Co0.7Cr0.1Zn0.2Fe2O4) and composites of polyaniline (PANI)- Co0.7Cr0.1Zn0.2Fe2O4 were prepared by polyacrylamide gel and in situ polymerization method, respectively, and then the synthesized materials were characterized by X-ray diffraction (XRD) and Fourier transform infrared spectrometer (FT-IR), their magnetic properties were measured using vibrating sample magnetometer (VSM) and their microwave absorbing capability was investigated by wave-guide method. The results show that the spinel Co0.7Cr0.1Zn0.2Fe2O4 ferrites and the composites PANI-Co0.7Cr0.1Zn0.2Fe2O4 are acquired. Because a small amount Co2+ ion of the octahedron ferrite is replaced by Cr3+ ions, the lattice constant of the Co0.8Zn0.2Fe2O4 ferrite reduces from 0.8409 nm to 0.8377 nm. The saturation magnetization (Ms), remanent magnetization (Mr) and coercive force (Hc) of the PPy-Co0.7Cr0.1Zn0.2Fe2O4 composites are 8.80 emu穏- 1, 3.14 emu穏- 1 and 37.22 kA穖- 1, respectively, which are smaller than that of the Co0.7Cr0.1Zn0.2Fe2O4 ferrite. In a measuring frequency range of 5.0-20.0 GHz, two peak values of reflection loss for the composites PPy-Co0.7Cr0.1Zn0.2Fe2O4 appear at 14.1 GHz and 17.9 GHz with -13.17 dB and -15.36 dB, respectively, which is obviously higher than those of the Co0.7Cr0.1Zn0.2Fe2O4 ferrite.