Influence of direct foaming methods on the early performance and microstructure of metakaolin‐based foam geopolymers. - Chen, Dawei; Zhang, Yajun; Wang, Wenxin; Shi, Yangpiaoxue; Mao, Jiaxi; Liu, Yi; Yan, Dongming; Chen, Shikun (International Journal of Applied Ceramic Technology, 2025)