Nghiên cứu khả năng chống ăn mòn mài mòn của lớp phủ hợp kim NiCr20 được thẩm thấu với photphat nhôm trong môi trường axit

The corrosive wear resistance of NiCr20 alloy coating (NC) impregnated by aluminum phosphate and heat-treated at 600 oC (NA6) and 1000 oC (NA10) was investigated in acid H2SO4 pH = 2 containing SiO2 3 % by weight; the flow velocity is 4 m/s. The analysis of X-ray diffraction (XRD) showed that, the stable crystalline phases in acidic media such as AlPO4 and Al(PO3)3 which were formed on NA6 coating’s surface made corrosive wear resistance of NA6 coating increase in comparison with the resistance measured on NA10 and NC coating samples. The formation of unstable crystalline phases such as Al36P36O144 and Ni3(PO4)2­ in NA10 coating caused the corrosive wear resistance of NA10 coating smaller than that one measured on NC coating. After 168 hours of corrosive wear test, the thickness of NA6 coating reduced to about 47 μm, while it was about 67 μm for NC coating. Keywords. Thermal spray, aluminum phosphate sealant, acidic corrosion, corrosion wear

Tổng hợp vật liệu bằng phương pháp phản ứng nổ và tính chất của LaPO4:Eu kích thước nanomet

Eu (III) -doped LaPO4 nanophosphors were prepared via combustion synthesis using urea as fuel and metal nitrates as precursor. Structures, morphologies, and photoluminescent properties of the LaPO4:Eu were studied by X-ray diffraction, scanning electron microscopy, photoluminescent and excitation photoluminescent spectra. The average diameters for the phosphor particles are 5-20 nm. The effects of Eu(III) doping process and heating temperature on structure and optical properties of nanophosphors have been investigated. LaPO4:Eu phosphors show the intense peak at 594 nm corresponding to the 5D0-7F1 transition of Eu (III) in inversion symmetry sites

Hoá học các nguyên tố hiếm và hoá phóng xạ

303 tr. ; 24 cm

Phổ hấp thụ electron của một số phức chất của nguyên tố đất hiếm với axit DL-2-amino-n-butyric

The electronic spectrum of some rare earth complexes with DL-2-amino-n-butyric acid have been recorded in the 400 ÷ 1100 nm region in water. It was found that the DL-2-amino-n-butyric acid utilized amino nitrogen and carboxyl oxygen for bonding