Weisong ZHAO
,
Wei ZHANG
,
Jinyu GUO
,
Boquan WANG
,
Jingdong GUO
,
Ke LU
材料科学技术（英）
The pure α-Ti samples were heated at an extremely high rate (~106 K/s) to the temperature of β phase zone followed by a rapidly quenching in an electro-pulsing treatment. After the treatment, micrometer-thick lamellar substructures were generated within the original equiaxed α-Ti coarse grains. Misorientations across adjacent lamellae are of a few degrees. The ultrafine lamellar substructures originated from a non-equilibrium α-β-α' phase transformation during rapidly heating-quenching process with a short exposure time at high temperatures. Tensile strength was increased by about 100 MPa due to the formation of the ultrafine lamellar substructure while the same tensile plasticity (elongation-to-failure) was maintained relative to the original sample. The strengthening effect could be attributed to the effective blockage of dislocation motions by a high density of sub-boundaries.
关键词:
Pure Ti
,
微结构
Shulan ZHANG
,
Huaining CHEN
,
Quanhong LIN
材料科学技术（英）
In this paper the preparation technique of surface nanocrystallization in commercial pure titanium was carried out by surface mechanical attrition treatment (SMAT). The mean grain size was calculated by using X-ray diffraction (XRD) and transmission electron microscope (TEM), and the results showed that the mean grain size of the surface was refined to nm level after SMAT treatment. Nanocrystallized surface layers were formed after treated for 5, 15, 30 and 60 min. Microhardness experimental results implied the microhardness obviously increased on the surface layer and it also showed the variation of microhardness at the cross section. Corrosion test results showed the corrosion resistance of the surfaces in the original commercial pure titanium treated by SMAT was not improved in HCl solution. The corrosion micrographs were observed by scanning electron microscope (SEM).
关键词:
Surface nanocrystallization
,
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