Exploratory Research On Diamagnetic Medical Cu-Si-Se Alloy

With the rapid application of magnetic resonance imaging(MRI) technology, the problem of MRI artifacts is urgently needed to be solved. Moreover, it is well known that some metallic materials could cause artifacts on MRI image. Currently, the newly developed MRI compatible materials mainly focus on the paramagnetic materials of low magnetic susceptibility. The experimental results showed that the diamagnetic metals hare have the lowest impact on MRI testing. In this work, the diamagnetic copper based alloys were optimally designed in order to develop a new type of compatible diamagnetic material.In this paper, the composition and heat treatment process of Cu-Si-Se alloys was studied to analyze its microstructure, mechanical and diamagnetism properties. In addition, preliminary investigations were made to enhance its corrosion resistance properties.. Based on results, the following conclusions were drawn.1.Orthogonal experimental results show that the optimal Cu-3Si-1.5Se alloy composition is Cu-3Si-1.5Se. The optimal heat treatment for Cu-3Si-1.5Se alloy was proposed to perform a solid solute at 850℃ for 1h, and then aging at 350℃ for 4h.2. After the optimal heat treatment, the ribbon and dot shaped Se-bearing precipitates were found to be distributed in Cu-3Si-1.5Se alloy matrix, and the EDS analysis results showed that the Se-bearing precipitates were Cu2-xSe. The experimental results showed that the grain size of Cu-3Si-1.5Se alloy was decreased with prolonging of the aging time, and the grain size was increased when aging temperature increased.3. The fracture found in Cu-3Si-1.5Se alloy was plastic fracture and the yield strength increased after aging heat treatment of the test alloy. With the increase of aging temperature, the corrosion rate of Cu-3Si-1.5Se alloy become faster, while with the increase of aging time, the corrosion rate of Cu-3Si-1.5Se alloy turned slower.4.Both Cu-3Si-1.5Se and Cu-3Si-0.5Se alloys were detected to be diamagnetic material and their diamagnetism increased with the increase of Se.5. Both surface oxidation treatment and BTA treatment can play the role of protection and preservation, whereas BTA treated alloy shows more corrosion resistant.