Bronze rings with graphite, as per your drawing, can be made using a variety of methods, but the most common ones are casting and powder metallurgy. The specific bronze alloy you mentioned, CuZn25Al6Mn3, is not directly mentioned in the search results, but the general process of making bronze rings should be applicable.

Casting Process

Casting is a common method for creating bronze rings. In this process, molten bronze is poured into a hollow mold to create the desired shape. The mold can be made from different materials, such as wax or sand, depending on the desired outcome and level of detail

Powder Metallurgy

Another method of making bronze rings involves the use of powder metallurgy. This process involves mixing powdered bronze and other elements, such as copper and tin, in specific proportions. Graphite can be mixed with the powder as a lubricant. The mixture is then cold molded under high pressure into the desired shape and then sintered in a reducing atmosphere to form the final product.

Finishing

After the ring is formed, it may undergo various finishing treatments or precision machining to achieve the final product as per the drawing.It’s important to note that the specific process used can vary depending on the exact requirements of the ring, including its size, shape, and intended use. Therefore, the manufacturing process should be tailored to meet these specific needs.