Why Is It Necessary To Verify The Purity Of Metal Powder For Additive Manufacturing In Dentistry?

Metal powder for Dental additive manufacturing should have stable physical and chemical properties. The purity of powder is one of the important indicators. In the process of powder preparation, the introduction of impurity elements such as oxygen, nitrogen and carbon should be used as an important verification aspect in terms of the preparation process. Take titanium alloy material as an example, with the increase of oxygen content, the plasticity of titanium alloy material, as a commonly used metal material in the preparation of dental restorations, will be greatly reduced, thus having serious influence on the hardness and mechanical properties of the final product. For metal powder of additive manufacturing, the oxygen content in chemical composition is an important factor affecting the printed piece. It is generally required that the oxygen content of titanium alloy powder should be controlled under 0.15%. Similarly, impurity elements such as nitrogen and carbon can also adversely affect the performance of the finished product and should be strictly controlled. Ceramic phase inclusions may be introduced during the preparation of powder due to melting and other factors. These refractory ceramic phase are mixed in the melting process of metal powder, which will prevent the metal powder from bonding well, easily causing internal defects of the printed body, and resulting in local performance degradation or even cracking of the printed body. Therefore, it is necessary to ensure that the metal powder has no ceramic phase inclusions, and need to verify the purity.