Original Article

Comparative study of microstructural evolution and mechanical behavior in automotive control arms processed from continuously cast ingots and extruded rods

¹ School of Materials and Metallurgy, University of Science and Technology Liaoning, Anshan 114009, PR China
² School of Materials Science and Engineering, Northeastern University, Shenyang, 110819, Liaoning, PR China
³ State Key Laboratory of Baiyumobo, Rare Earth Resource Researches and Comprehensive Utilization, Baotou Research Institute of Rare Earths, Baotou, 014030, Nei Mongol Inner Mongolia, PR China

^* e-mail: This email address is being protected from spambots. You need JavaScript enabled to view it.

Received: 11 June 2025
Accepted: 27 August 2025

Abstract

6082 aluminum alloy forging is widely used in automotive Industry to produce control arms, with extruded rods currently serving as the primary feedstock material. However, this approach often leads to abnormal grain growth during heat treatment, resulting in degraded mechanical properties. Alternatively, using continuously cast ingots of equivalent diameter as feedstock not only mitigates grain growth but also reduces production costs. This study systematically compares the microstructure and mechanical properties of control arms fabricated from continuously cast ingots and extruded rods using optical microscopy (OM), scanning electron microscopy (SEM), hardness testing, and tensile testing. The findings reveal that control arms produced from continuously cast ingots exhibit a finer average grain size and a higher volume fraction of uniformly dispersed secondary phases compared to those fabricated from extruded rods. The tensile strength, yield strength, elongation, and microhardness of the components produced from continuously cast ingot reached 350 MPa, 300 MPa, 16.5%, and 122.7 HV0.1, respectively. These values represent a 7.7% increase in tensile strength, a substantial 20% enhancement in yield strength, and a 3% improvement in microhardness over the components made from extruded rods, while maintaining excellent ductility.