Grain Refinement of a Powder Nickel-Base Superalloy Using Hot Deformation and Slow-Cooling
| Autor: | Xiaofeng Wang, Xianqiang Fan, Jinwen Zou, Jie Yang, Zhipeng Guo |
|---|---|
| Rok vydání: | 2018 |
| Předmět: |
Materials science
cooling 02 engineering and technology lcsh:Technology 01 natural sciences Article hot deformation Condensed Matter::Materials Science nickel-base superalloy 0103 physical sciences General Materials Science Composite material lcsh:Microscopy lcsh:QC120-168.85 010302 applied physics twining lcsh:QH201-278.5 lcsh:T Recrystallization (metallurgy) 021001 nanoscience & nanotechnology Microstructure γ’ precipitates Grain size Superalloy lcsh:TA1-2040 lcsh:Descriptive and experimental mechanics Grain boundary lcsh:Electrical engineering. Electronics. Nuclear engineering Crystallite Dislocation lcsh:Engineering (General). Civil engineering (General) 0210 nano-technology Crystal twinning lcsh:TK1-9971 |
| Zdroj: | Materials Volume 11 Issue 10 Materials, Vol 11, Iss 10, p 1978 (2018) |
| ISSN: | 1996-1944 |
| Popis: | A pre-hot-deformation process was applied for a polycrystalline nickel-base superalloy to active deformation twins and dislocations, and subsequent slow cooling treatment was used to achieve grain refinement and microstructure homogenization. The microstructural evolution of the alloy was investigated, and the corresponding underlying mechanism was discussed. It was found that twinning mainly occurred in large grains during pre-hot-deformation owing to the stress concentration surrounding the large grains. High density dislocations were found in large grains, and the dislocation density increased approaching the grain boundary. The average grain size was refined from 30 &mu m to 13 &mu m after slow cooling with a standard deviation of grain size decreasing from 10.8 to 2.8, indicating a homogeneous microstructure. The grain refinement and microstructure homogenization during cooling process could be achieved via (i) static recrystallization (SRX), (ii) interaction of twin tips and &gamma &rsquo precipitates, and (iii) grain coarsening hindered by &gamma precipitates in grain boundaries. |
| Databáze: | OpenAIRE |
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