In this master thesis, a topic entitled "Specific areas of application of copper alloys" is processed. In the theoretical part of the paper, copper and its alloys - bronze and brass - are generally described. The chemical compositions of alloys, phase diagrams, some physical and mechanical properties and applications are presented. Special attention is paid to beryllium bronze, which is actually low-alloyed copper (contains about 2% Be), but due to its importance and specific areas of application is considered to be copper alloy. In the experimental part of the paper, the problem is the selection of additional material for the repair welding of a segment of the mold which is made of beryllium bronze. 3 specimens were made and a layer of different additional material was welded on each of them. As it is a part of a mold for casting aluminum, the bronze segment is exposed to erosion wear, and for the additional material is selected the one that shows the best results after the hardness test. It was concluded that the additional material used in specimens GC03 or GC01 would be used as an additional material when welding the bronze segment. When choosing an additional material for welding, in addition to hardness, the price of additional material as well as its welding behavior will be taken into account.