How to deal with the surface defect reaction layer of titanium plate and titanium rod

The surface reaction layer of Gr5 Ti-6Al-4V Titanium Plate and medical titanium rod is the main factor affecting the physical and chemical properties of titanium workpiece. Before processing, the surface pollution layer and defect layer must be completely removed. Physical and mechanical polishing of titanium plate and titanium rod surface polishing process:

1. Sandblasting:

The sandblasting treatment of titanium wire castings is generally better to use white corundum, and the sandblasting pressure is smaller than that of non-precious metals, generally controlled below 0.45MPa. Because, when the injection pressure is too large, the sand particles impact the titanium surface to generate intense sparks, and the temperature rise can react with the titanium surface, resulting in secondary pollution and affecting the surface quality. The time is 15-30 seconds, and only the sticky sand, surface sintered layer, and part of the oxide layer on the surface of the casting can be removed. The rest of the surface reaction layer structure should be quickly removed by chemical pickling.

2. Pickling:

Pickling can quickly and completely remove the surface reaction layer without contamination of the surface with other elements. Both HF-HCL series and HF-HNO3 series pickling liquids can be used for titanium pickling, but HF-HCL series pickling liquids have a large amount of hydrogen absorption, while HF-HNO3 series pickling liquids have a small hydrogen absorption capacity, which can control HNO3 The concentration of HF can reduce the absorption of hydrogen, and the surface can be brightly treated. Generally, the concentration of HF is about 3%-5%, and the concentration of HNO3 is about 15%-30%.