Suzhen LUO
,
Yugui ZHENG
,
Wei LIU
,
Heming JING
,
Zhiming YAO
,
Wei KE
材料科学技术（英文）
The cavitation erosion (CE) behavior of CrMnN ferrite-austenite duplex stainless steel in distilled water and 3% NaCl solution was investigated by using a magnetostrictive-induced CE facility. The damaged surfaces were observed by scanning electron microscope (SEM). It was found that the CE resistance of CrMnN steel was higher than that of 0Cr13Ni5Mo steel. The mass loss rate of CrMnN steel in distilled water was similar to that in 3% NaCl except at the early stage of CE. The failure mode of ferrite phase was brittle fracture, which had adverse effect on the resistance to CE, while the failure of austenite phase was a ductile failure in CrMnN steel. The excellent resistance to CE was related to the good mechanical properties of austenitic phase and the consumption of CE energy by plastic deformation involving slip and twinning.
关键词:
Cavitation erosion
,
null
,
null
Xingwen YU
,
Chunan CAO
,
Chuanwei YAN
,
Zhiming YAO
材料科学技术（英文）
A new method for corrosion protection of Al-based metal matrix composites (MMC) was developed using two-step process, which involves anodizing in H2SO4 solution and sealing in rare earth solution. Corrosion resistance of the treated surface was evaluated with polarization curves. The results showed that the effect of the protection using rare earth sealing is equivalent to that using chromate sealing for Al6061/SiCp. The rare earth metal salt can be an alternative to the toxic chromate for sealing anodized Al MMC.
关键词:
Applied Physics a-Materials Science & Processing
Amorphous aluminate YAlO3 (YAO) thin films on n-type silicon wafers as gate dielectric layers of metal - oxide semiconductor devices are prepared by pulsed laser deposition. As a comparison, amorphous aluminate LaAlO3 (LAO) thin films are also prepared. The structural and electrical characterization shows that the as-prepared YAO films remain amorphous until 900 degrees C and the dielectric constant is similar to 14. The measured leakage current of less than 10(-3) A/cm(2) at a bias of V-G = 1.0 V for similar to 40-nm-thick YAO and LAO films obeys the Fowler Nordheim tunneling mechanism. It is revealed that the electrical property can be significantly affected by the oxygen pressure during deposition and post rapid thermal annealing, which may change the fixed negative charge density at the gate interface.
关键词:
hafnium oxide;si;stability;silicon;transition;dioxide;devices;hfo2
