Xinhua LI
,
Kai QIU
,
Fei ZHONG
,
Zhijun YIN
,
Changjian JI
,
Yuqi WANG
,
null
,
null
,
null
,
null
,
null
,
null
材料科学技术（英文）
The preparation of porous structure on the molecular beam epitaxy (MBE)-grown mixed-polarity GaN epilayers was reported by using the wet chemical etching method. The effect of this porous structure on the residual stress of subsequent-growth GaN epilayers was studied by Raman and photoluminescence (PL) spectrum. Substantial decrease in the biaxial stresse can be achieved by employing the porous buffers in the hydride vapour phase epitaxy (HVPE) epilayer growth.
关键词:
GaN
,
vapour
,
phase
,
epitaxy
Zhonggang SUN
金属学报(英文版)
The TEM and HRTEM were utilized to investigate the phase transformation of hydrogenated Ti-6Al-4V alloys (0 wtpct-0.9 wt pct H) treated by annealing and quenching from β field. The results indicate that the orthorhombic α'' martensite and β phase appear progressively with the increase of hydrogen concentration. On the other hand, hydrides with sizes of 2-5 nm are observed in the specimens containing more than 0.6 wt pct hydrogen. The formation of α'' and twins can be attributed to the internal stress caused by solid solution of hydrogen and hydrides precipitation.
关键词:
Ti-6Al-4V alloys
,
Martensitic transformation
,
Hydrogenation
,
Hydride
