Method for manufacturing a metal part with bi-metallic characteristic and manufacturing arrangement for conducting said method

Manufacturing arrangement for manufacturing a metal part with bi-metallic characteristic in an additive manufacturing process, by:

• a) providing a first powder of a metal with a first thermal expansion coefficient;
• b) providing a second powder of a metal with a second thermal expansion coefficient different from said first thermal expansion coefficient;
• c) manufacturing a first pure metal layer by successively melting layers of said first powder alone;
• d) manufacturing on said first pure metal layer a mixed layer by successively melting layers of a third powder being a mixture of said first and second powders, whereby the percentage of said first powder decreases from 100% to 0% with increasing thickness of said mixed layer, and whereby the percentage of said second powder increases at the same time from 0% to 100%;
• and
• e) manufacturing a second pure metal layer by successively melting layers of said second powder alone, the arrangement comprising:
• at least two powder reservoirs, which are connected with their outlets to a mixer for mixing powders from the at least two powder reservoirs to provide at its outlet a mixed powder, further comprising a powder layer generating device, which receives the mixed powder from the mixer and generates a powder layer of the mixed powder on a support, and comprising a powder melting means, which interacts with the powder layer to melt the powder layer.