Application of electron beam processing and sintering to create porous–monolithic materials based on NiTi

NiTi-based porous–monolithic materials represent a promising class of biocompatible structures that combine the advantages of monolithic and porous structures. The monolithic base of these materials provides high strength and deformation properties necessary for performing structural functions in the body. At the same time, the porous surface layer with a developed surface mimicking the trabecular structure of bone promotes bone and connective tissue ingrowth, accelerating the process of implant osseointegration. Such materials are particularly in demand in traumatology, orthopedics, and maxillofacial surgery for the repair of segmental bone defects.

The objective of this study is to develop a method for producing a new class of corrosion-resistant, superelastic, porous–monolithic material based on NiTi.
Optical and scanning electron microscopy, X-ray diffraction, and energy-dispersive microanalysis were used to solve these problems. The average pore size and size distribution were determined using a stereometric method. The porosity coefficient was determined by weighing. Corrosion resistance parameters were determined by voltammetry using polarization curves.
As a result of this study, a method was developed for creating a porous–monolithic material based on titanium nickelide with a sintering temperature lowered by 150 K and a high-quality, uniform transition layer between the porous and monolithic parts. The novelty of these results lies in the possibility of reducing the sintering temperature and achieving high structural parameters for the porous–monolithic material based on NiTi. Optimal electron-beam processing parameters were established to ensure the formation of a porous layer of uniform phase composition (primary phases B2 and B19') on the surface without the precipitation of secondary intermetallic compounds. Controlled surface roughness with Ra ≥ 50 µm was achieved.