How far has metal 3D printing technology been developed?

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Note that specifically refers to the 3D printing technology, materials and application categories that use metal raw materials, including but not limited to SLS, SLM, EBM technology, as well as spherical titanium powder, stainless steel powder, etc. I hope everyone can speak a little deeper in the field you are familiar with, and then speak a little more in simple terms. Grateful thanks!