**Preparation and Characterization of Mg-RE Alloy Sheets and Formation of Amorphous**/**Crystalline Composites by Twin Roll Casting for Biomedical Implant Application**

### **Haijian Wang 1, Dongying Ju 2,3,\* and Haiwei Wang 4,5**


Received: 27 August 2019; Accepted: 1 October 2019; Published: 3 October 2019

**Abstract:** A new type of Mg-based metallic glass has attracted extensive attention due to its excellent corrosion resistance and favorable biocompatibility. In this study, an amorphous/crystalline composite Mg-RE alloy sheet was prepared by a vertical type twin roll caster (VTRC) method, and its microstructure was characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), and electron probe micro-analysis (EPMA) and transmission electron microscopy (TEM); furthermore, the corrosion behaviors of the Mg-RE alloy sheet were investigated in PBS solution using electrochemical techniques and immersion testing in a simulated physiological condition. Furthermore, it was implanted into the femur of rats to explore its prospect as biological transplantation material. Its microscopic characterization experiments show that the crystal structure is crystalline phase containing amorphous phase. Electrochemical experiments and immersion testing both showed that Mg-RE(La,Ce) sheet with VTRC has a better corrosion resistance than master alloy, and a uniform corrosion layer on the surface. In vivo, as an implant material, tests show that Mg-RE alloy sheets have better biocompatibility and induce new bone formation, and they can be expected to be utilized as implant materials in the future.

**Keywords:** metallic glass; twin roll casting; GFA; MicroCT
