It is most likely made of welded titanium particles as others point out.
Imagine a thin layer of titanium dust. Then shine a laser on the points where you want to weld. When done, add another layer over it and repeat.
Or imagine a nozzle which sprays titanium dust. Directly after the nozzle there is a focused laser point. When the dust goes through the laser it welds together. So when you do this close to a titanium surface you can add more titanium to it.
And there are other methods for 3D printing metal. But most of them are just advanced welding techniques.
Imagine a thin layer of titanium dust. Then shine a laser on the points where you want to weld. When done, add another layer over it and repeat.
Or imagine a nozzle which sprays titanium dust. Directly after the nozzle there is a focused laser point. When the dust goes through the laser it welds together. So when you do this close to a titanium surface you can add more titanium to it.
And there are other methods for 3D printing metal. But most of them are just advanced welding techniques.