Which of the following materials often adds resistance to wearing in engineering applications?

Bronze is often chosen in engineering applications for its excellent wear resistance. This is due to its composition, which typically includes copper and tin, and sometimes other elements such as phosphorus, aluminum, or silicon. The specific attributes of bronze, including its hardness and natural lubrication properties, help minimize friction and wear in machinery and components that are subject to constant movement and abrasion. These characteristics make bronze particularly suitable for applications involving bearings, gears, and various mechanical parts that experience repetitive motion.

In contrast, while cast iron and aluminum may be used in various engineering contexts, their resistance to wear is not as effective as bronze. Copper, while an excellent electrical conductor, does not provide the wear resistance that is often required in demanding applications.