In the fields of new energy, electric vehicles (EVs), aerospace, and high-end industrial equipment, bimetallic material joining has become a key trend in product development. Engineers leverage the distinct properties of different metals—such as the lightweight of aluminum, the high strength of steel, and the electrical and thermal conductivity of copper—to achieve an optimal balance of weight, performance, and cost. However, bimetallic assemblies also present high machining risks and long-term reliability challenges, requiring mature engineering strategies and process control.