The adhesion of diamond-like carbon (DLC) films on steel is usually very poor. Adhesion of DLC on SKD11 steel was improved for tribological purposes in this study by applying chromium (Cr) metal intermediate layers using magnetron sputtering with substrate bias. DLC films were deposited by inductively coupled plasma (ICP) chemical vapor deposition. However, the adhesion was only at medium level. Intermixing at the Cr-steel interface was further achieved by ion bombardment and found to remarkably improve the adhesion. A reliable process was established to improve the adhesion to top level. (c) 2004 Elsevier B.V. All rights reserved.