Comparison of the Crystal Structure and Wear Resistance of Co-Based Alloys with Low Carbon Content Manufactured by Selective Laser Sintering and Powder Injection Molding

Abstract

Cobalt alloys are widely used in biomedicine, implantology, and dentistry due to their high corrosion resistance and good mechanical properties. The high carbon improves the wear properties, but causes fragility and dangerous cracking of elements during use. The aim of the present work was to analyze and compare the structure and wear resistance of Co-based alloy samples with low carbon content, produced by Selective Laser Sintering (SLS) and Powder Injection Molding (PIM). Structure characterization, mainly with the use of transmission electron microscopy, was applied to investigate the differences in tribological properties. The better resistance to abrasive wear for SLS was explained by the presence of a hard, intermetallic phase, present as precipitates limited in size and evenly distributed in the cobalt matrix. The second factor was the structure of the cobalt matrix, with dominant content of the hexagonal phase. By combining the characteristic features of the matrix and the reinforcing phase, the analyzed material gains an additional advantage, namely a higher resistance to abrasive wear.

Structure and Properties of Co-Cr-Mo Alloy Manufactured by Powder Injection Molding Method

“…The σ phase composition was confirmed by the electron diffraction ( Figure 10 f). Occurrence of the sigma phase surrounding different precipitation or as a binary eutectic has already been demonstrated in earlier studies [ 31 , 32 ]. In this case, the core is chromium nitride, which may arise from the fact that chromium increases the solubility of nitrogen in a cobalt matrix [ 33 ].…”

3D and 4D printing in dentistry and maxillofacial surgery: Printing techniques, materials, and applications

“…This transformation occurs at relatively slow cooling rates. Since the transition from FCC to HCP is kinetically arrested at room temperature, the main crystalline structure of Co-based alloys is unstable FCC structure [120]. Transformation from FCC to HCP crystalline structure only occurs at high temperature after long-term exposure and/or application of mechanical stress.…”

Evaluation of Bacterial Adhesion to the ZrO2 Atomic Layer Deposited on the Surface of Cobalt-Chromium Dental Alloy Produced by DMLS Method

“…This is due to the fact that the adhesion of bacteria to the prosthetic surfaces of metal materials is one of the main factors influencing the durability of the restoration and the condition of the oral cavity and the user’s entire body. For this purpose, newer and newer solutions are being sought, such as surface modification methods that would allow the elimination of unfavorable phenomena related to the deposition of bacteria [ 14 , 15 ].…”