Recent materials play a significant role in the acquisition of technological innovation capacity for new products, and with technological complexity gradually increasing, it is necessary to integrate technological knowledge such as technology convergence to interpret technological innovation. In this context, accurately understanding technology convergence of materials and predicting promising technology convergence is essential to securing continued national and corporate competitiveness. Therefore, this study investigated technology convergence in the material field focused on automotive lightweight materials. The data were extracted from the Korean Intellectual Property Office, to which the methodologies of technology convergence ratio, similarity measures, and network analysis were applied. Our findings are as follows: (1) the proportion of patents containing technology convergence increases over time, and the convergence between technology fields in mechanical engineering is more active than between technology fields in chemistry; (2) convergence between a few core technologies within the network is weakening, and a new and strengthening pattern of technology convergence can be confirmed; (3) the network is more complex and the convergence of different areas of technology is increasing. These results enable an accurate understanding of the present and future of technology convergence and support government initiatives.