On interfacial velocities during abnormal grain growth at ultra-high driving forces

Study of rapid grain boundary migration in a nanocrystalline Ni thin film

“…Similar studies on abnormal grain growth in Ni using in situ TEM have been carried out, notably by Hibbard et al [9,40]. The results from that study were similar in that the sporadic and unpredictable behavior of grain growth was observed.…”

“…Examples of this instability include the observation of grain growth, including abnormal grain growth, at temperatures below 600 K in Au [1][2][3], Cu [2], Pd [4], and Ni [5][6][7][8][9][10][11][12]. The observation of abnormal grain growth has been attributed to the initial microstructure, including the distribution of the grain size, misorientation, grain boundary energy and mobility, triple junction mobility, impurities, microstrain, topological features such as curvature and number of boundary faces, etc.…”

“…This growth proceeds in a sporadic start/stop fashion and lacks a characteristic growth rate. Past in situ TEM experiments that focused on growth front velocities have suggested that this start/stop growth results from the accumulation of impurity elements at the grain boundaries [9]. Experiments on the texture development in annealed electrodeposited nanocrystalline Ni revealed the development of a 1 1 1 //ND texture via a twinning mechanism [10] with some studies also reporting an initial 1 1 4 //ND texture [11].…”

Electrodeposited Nanocrystalline Metals, Alloys, and Composites

“…There are numerous reports of studies of the thermal stability and grain growth in electrodeposited nanocrystalline Ni, [60,107,[175][176][177][178][179][180][181][182][183][184][185][186] Ni-P alloys, [52,55,65,66,[187][188][189][190] Ni-Fe alloys, [60,107,191,192] Pd-Fe alloys, [25,193] Co, [185,194,195] Co-P alloys, [196] Ni-Co alloys, [197] and Ni-W alloys. [198] Recent reviews of the thermal stability of nanocrystalline electrodeposits are given in Refs.…”

Initial texture effects on the thermal stability and grain growth behavior of nanocrystalline Ni thin films

“…With their promise of superior properties such as improved mechanical strength [1][2][3] and fatigue resistance [4,5], nanocrystalline materials continue to be an area of active research. However, due to the high volume-fraction of grain boundaries in comparison to coarse-grained materials, these materials tend to be unstable even at low homologous temperatures, resulting in significant grain coarsening over relatively short time periods [6][7][8][9][10][11][12][13][14][15]. Efforts to understand this growth, including strategies to stabilize nanocrystalline structures or promote the development of favorable microstructures, promise to provide greater control in the development and application of nanocrystalline materials [16][17][18].…”