UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K Form 20-F x Form 40-F ¨ This Form 6-K is incorporated by reference into the registrant's Registration Statement on Form F-3 (File No. 333-213649). Second Quarter 2025 Financial Results Except as otherwise required by the context, references to "Materialise," "Company," "we," "us" and "our" are to Materialise NV and its subsidiaries. Second Quarter 2025 Results REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 U ...