Effect of diffusion of Ni and B on the microstructure and hardness of Ti Cp

Microstructure and Mechanical Properties of NiTi<sub>2</sub>-TiB Composite Fabricated by Spark Plasma Sintering

“…There are three intermetallic compounds in the Ni-Ti system, Ni 3 Ti, NiTi and NiTi 2 , among which NiTi has received much interest for its shape memory effect [1]. NiTi 2 has favorable properties such as high corrosion resistance and wear resistance and Coating of Ti base alloys by NiTi 2 films has been examined [2]- [4]. On the other hand, bulk application of NiTi 2 has not been reported probably because of its poor ductility caused by the complicated E93-type lattice structure which contains 96 atoms in a unit cell [5].…”

Katodik Ark Plazma İşlemi Kullanılarak Titanyum Yüzeylerinin Nikel İle Alaşımlandırılması

“…When the treatment temperature increased, concentration of α-Ti increased as well. The diffusion layer thicknesses are almost two times higher when compared to studies conducted using Ni-Ti bulk material couples [10] which can be attributed to elimination of diffusion barriers and flow of current through the substrate during the treatment [3].…”

“…The difference in nickel content of these layers might be the reason of the morphological change. According to Rampin [10] Widmanstatten structure formation is diffusioncontrolled process and can form at low nickel concentrations. During the formation of this structure, α phase is nucleated at the β grain boundaries.…”

“…Diffusion in the binary Ni-Ti system has been the subject of a substantial number of studies aiming mainly to investigate the diffusion behavior between these two metals for powder metallurgy and brazing applications [1][2][3][4][5][6][7][8][9][10]. The major goal in these studies was to obtain and understand the mechanism of formation of the well-known NiTi phase by solid-state diffusion processes.…”

“…Beside these studies, some resarchers studied the effect of the external current of heating rate on the phase formations [3,7,8]. Application of external current to the samples increased the diffusion rate at the study of Garay et al A coating/diffusion process of Ni-Ti system was studied by Rampin et al [10]. They investigated the heat treatment temperature effect on the diffusion of Ni, resulting microstructure and hardness of titanium substrate.…”