A multi-material structure includes a refractory portion with a metal or metal alloy of at least one of niobium (Nb), molybdenum (Mo), tantalum (Ta), tungsten (W), rhenium (Re), iridium (Ir), vanadium (V), and ruthenium (Ru). A structural portion is metallurgically joined with the refractory portion. The structural portion includes a titanium (Ti) alloy. At least one of the refractory and structural portions is additively manufactured.

The invention relates to a stainless steel blank for making a Damascus patterned article, wherein the steel blank is made from at least two different nitrogen alloyed stainless steels having a chromium content of 11-25 weight %, of which at least one of the steels comprises nitrogen in an amount of 0.10-5.0 weight % and, optionally, at least one of the steels comprises nitrogen in an amount of 0.01-0.5 weight %.

The disclosure discloses a polycrystalline diamond composite sheet having a continuous gradient transition layer and a 3D printing preparation method thereof. The polycrystalline diamond composite sheet consists of a polycrystalline diamond layer, a continuous gradient transition layer, and a cemented carbide substrate from top to bottom, in which the continuous gradient transition layer consists of diamond and cemented carbide. Along a direction from the cemented carbide substrate to the polycrystalline diamond layer, a content of the cemented carbide in the continuous gradient transition layer decreases from 100% to 0, and a content of the diamond increases from 0 to 100%. By designing and combining the continuous gradient transition layer with 3D printing technology, the disclosure realizes a continuous change in the two materials of diamond and cemented carbide, thereby eliminating the sudden change interface of the materials inside the diamond composite sheet.

A copper paste for joining contains metal particles and a dispersion medium, in which the copper paste for joining contains copper particles as the metal particles, and the copper paste for joining contains dihydroterpineol as the dispersion medium. A method for manufacturing a joined body is a method for manufacturing a joined body which includes a first member, a second member, and a joining portion that joins the first member and the second member, the method including: a first step of printing the above-described copper paste for joining to at least one joining surface of the first member and the second member to prepare a laminate having a laminate structure in which the first member, the copper paste for joining, and the second member are laminated in this order; and a second step of sintering the copper paste for joining of the laminate.