Effects of ECAE process on microstructure and transformation behavior of TiNi shape memory alloy

Li, Xijun; Xiang, Guoquan; Cheng, Xinbin

doi:10.1016/j.matdes.2004.10.025

Cited by 31 publications

(12 citation statements)

References 18 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This dramatic increase in the transformation temperature peak at 873 K was implicitly reported in Refs. [14,15], in which the re-crystallization may give rise to the increase of transformation temperatures. The mechanism of the effect of re-crystallization on phase transformation, however, remains obscure in their report.…”

Section: Effects Of Heat Treatment On Transformation Behaviorsmentioning

confidence: 99%

Transformation characteristics of TiNi/TiNi alloys synthesized by explosive welding

Zheng

Cui

2007

Front. Mater. Sci. China

View full text Add to dashboard Cite

Effects of severe deformation and heat treatment on the transformation behaviors of explosively welded duplex TiNi/TiNi shape memory alloys (SMAs) were investigated by the differential scanning calorimeter (DSC). The explosively welded duplex TiNi/TiNi plate of 0.7 mm in thickness was cold-rolled at room temperature to the extent of 60% reduction in thickness and then annealed at different temperatures (573-973 K) for different time (15 min-10 h). Low temperature (623-723 K) heat treatment led to amorphous crystallization. At higher temperature (873 K), the re-crystallization took place in the specimens. Analysis showed that the change of internal stresses is just the root cause of the change of transformation temperature. The relationships between the transformation behaviors and the heat treatment were discussed in the present report.

show abstract

Section: Effects Of Heat Treatment On Transformation Behaviorsmentioning

confidence: 99%

Transformation characteristics of TiNi/TiNi alloys synthesized by explosive welding

Zheng

Cui

2007

Front. Mater. Sci. China

View full text Add to dashboard Cite

show abstract

“…It was reported that significant grain refinement occurred after applying ECAE, which increased the strength of an alloy [1]. ECAE has been successfully used for various metals such as copper [2][3][4], Al alloys [5][6][7][8] and Ti alloys [9,10]. However, these studies mainly focus on the effect of ECAE on microstructure and mechanical properties of alloys.…”

Section: Introductionmentioning

confidence: 99%

Effect of ECAE on Microstructure and Tribological Properties of Cu–10%Al–4%Fe Alloy

Gao

Cheng

2007

Tribol Lett

View full text Add to dashboard Cite

Equal channel angular extrusion (ECAE) process was carried out for a commercial aluminum bronze alloy (Cu-10%Al-4%Fe) produced by hotrolling at high temperature. The effect of ECAE on microstructure, mechanical, and tribological properties of the alloy was investigated. Experimental results showed that the grain size of the alloy decreased with the increase of the pass number of ECAE. After applying ECAE with six passes, the hardness and yield strength of the alloy increased from 118 kgf/mm 2 and 356 MPa to 165 kgf/mm 2 and 588 MPa, respectively. The friction coefficient and wear rate of the aluminum bronze alloy were largely reduced due to the improvement of mechanical properties after ECAE. The adhesive wear was the primary wear mechanism for the specimen without ECAE, while abrasive wear was dominant for the specimen with ECAE after six passes.

show abstract

“…The M;,) and M pz values changed slightly during heat-treatments above 873 K in the cooling process. Reverse martensitic transformation peak temperatures (A p ), A pz and A p3 ) of the specimens, which were annealed over 873 K, increased remarkably, compared with those annealed below 873 K. This dramatic increase in peak temperature of reverse martensitic transformation was implicitly due to re-crystallization (Li, et al, 2005;2006). The mechanism nanocrystalline structure under post-deformation annealing in a temperature range from 473 to 673 K (Khmelevskaya, et al, 2003a;2003b;Sergueeva, et al, 2003;Brailovski, et al, 2004).…”

Section: Effect Of Post-deformation Annealingmentioning

confidence: 93%

Effects of severe plastic deformation and heat treatment on transformation behavior of explosively welded duplex TiNi−TiNi

Zheng

Cui

2007

Pet. Sci.

View full text Add to dashboard Cite

The effects of severe plastic deformation and heat treatment on the transformation behavior of explosively welded duplex TiNi-TiNi shape memory alloys (SMAs) were investigated by differential scanning calorimeter (DSC) measurements. The explosively welded duplex TiNi-TiNi plate of 0.7 mm thickness was cold-rolled at room temperature to a 60% reduction in thickness and then annealed at different temperatures for different durations. The results showed that low temperature (623-723K) heat-treatment led to the crystallization of the amorphous region, and re-crystallization occurred in the specimens annealed at higher temperatures (over 873 K). Research indicated that the change of martensitic transformation temperature is due to the change of internal stresses with increasing heat treatment temperature. The change of annealing time also led to a change in martensitic transformation temperature, which was associated with the precipitation and decomposition of Ti 3Ni4 in TiNi-l. Table 1 Transformation temperatures of original materialsSpecimens of 10 mmx l S mm were spark cut from the 0.7 mm thick sheet of explosively welded duplex TiNi-TiNi SMAs. They were cold rolled at room temperature to a 60% reduction in thickness. During the cold rolling, the duplex TiNi-TiNi sheets were sandwiched by stainless steel sheets to prevent fracture. After being cold rolled, the duplex sheet was submitted to various annealing treatments. A large range of annealing temperatures (from 573 to 973 K) and time durations (from 15 min to 10 h) were selected for the vacuum annealing under a pressure lower than 1.0xlO-2 Pa. The ExperimentalThe specimens used were explosively welded duplex TiNi-TiNi shape memory alloys. The two TiNi plates used for welding had dimensions of 200 mmx 100 mmx l mm. The chemical composition of TiNi-l was Ni-50.2 at% Ti and TiNi-2 was Ni-50 at% Ti. The transformation temperatures of these two TiNi plates measured with a differential scanning calorimeter (DSC) before welding are listed in Table 1, where M; M r , M p , As, A r and A p are the starting, finishing and peak temperatures of the martensitic and reverse martensitic transformation, respectively.

show abstract

Effects of ECAE process on microstructure and transformation behavior of TiNi shape memory alloy

Cited by 31 publications

References 18 publications

Transformation characteristics of TiNi/TiNi alloys synthesized by explosive welding

Transformation characteristics of TiNi/TiNi alloys synthesized by explosive welding

Effect of ECAE on Microstructure and Tribological Properties of Cu–10%Al–4%Fe Alloy

Effects of severe plastic deformation and heat treatment on transformation behavior of explosively welded duplex TiNi−TiNi

Contact Info

Product

Resources

About