A study on hot deformation behavior of Ni-42.5Ti-7.5Cu alloy

Abstract

h i g h l i g h t sFlow stress behavior of Ni-42.5Ti-7.5Cu studied and modeled for the first time. The model considered the compensation of both strain and strain rate. DRX was postponed when logarithm of Z parameter was around 33 at strain rate of 0.001 s À1 and 900 C. Ti(NiCu) 2 Precipitates, formed via SIP during deformation, postponed DRX. a r t i c l e i n f o t r a c tTo investigate the hot deformation behavior of the Ni-42.5Ti-7.5Cu (wt%) alloy, hot compression tests were carried out at the temperatures from 800 C to 1000 C and at the strain rates of 0.001 s À1 to 1 s À1 . The results show that the occurrence of dynamic recrystallization (DRX) is the dominate restoration mechanism during the hot deformation of this alloy. There is an increase in peak and steady state stresses with decreasing the deformation temperature and increasing the strain rate. The experimental results were then used to determine the constants of developed constitutive equations. There is a good agreement between the measured and predicted results indicating a high accuracy of developed model. ZenereHollomon (Z) parameter, calculated based on the developed model, indicates that DRX was postponed when the logarithm of the ZenereHollomon parameter fell around 33 at strain rate of 0.001 s À1 and temperature of 900 C. This phenomenon can be regarded as the interactions between solute atoms and mobile dislocations. The established constitutive equations can be used to predict and analyze the hot deformation behavior of Ni-42.5Ti-7.5Cu alloy.

On the Coupling between Recrystallization and Precipitation Following Hot Deformation in a γ-γ′ Nickel-Based Superalloy

“…The q 1075 , q 1000 and q 400 samples were slow cooled down to 1075 °C, 1000 °C and 400°C respectively at 19.5 °C/min and then water quenched. 4 Figure 1: thermomechanical path applied to produce the five studied samples.…”

“…Thus, the fine γ' precipitation is mainly controlled by the cooling conditions, while the grain structure is controlled by dynamic and post-dynamic recrystallization occurring during hot forging and cooling, respectively. Kinetics of static [1], dynamic [2,3,4,5,6,7], and post-dynamic [8,9,10] recrystallization in Nickel-based superalloys have already been addressed in the literature.…”

Deformation Behavior and Microstructure Evolution of NiTiCu Shape Memory Alloy Subjected to Plastic Deformation at High Temperatures

“…Consequently, it is very important to understand deformation behavior as well as microstructural evolution of NiTi-based SMAs at high temperatures [16][17][18][19][20]. Up to date, many scholars have devoted themselves to studying the flow behavior of NiTi-based SMAs at high temperatures based on the Arrhenius-type constitutive equation [21][22][23][24][25], which lays the foundation for clarifying deformation mechanisms of NiTi-based SMAs.…”

“…Arrhenius-type constitutive equation [21][22][23][24][25], which lays the foundation for clarifying deformation mechanisms of NiTi-based SMAs.…”

Investigation of Dynamic Recrystallization of NiTi Shape Memory Alloy Subjected to Local Canning Compression

“…It is well known that plastic deformation at high temperatures is of great importance in manufacturing the products of NiTi-based SMAs [3][4][5]. In particular, dynamic recrystallization (DRX) frequently occurs during plastic deformation of NiTi-based SMAs at high temperatures [6][7][8][9].…”