Statistical Wear Tracking Protocol Implementation for Hardened Shutoff Lands
Implement press-side optical profilometry and statistical Cpk limits to track hardened shutoff land recession, triggering precision refurbishment before resin flash occurs.
VDI 3198
Meaning
Standardized visual indentation test procedures evaluate adhesion strength and delamination resistance of hard thin film coatings applied to hardened tool steel surfaces. Tooling specifications cite vdi 3198 to verify physical bonding quality of physical vapor deposition coatings on injection mold inserts. A Rockwell C diamond indenter produces a localized surface impression, and microscopic evaluation categorizes crack patterns into quality classes.
Assessment applies strictly to hard coatings applied on substrates hardened above fifty four Rockwell C.
Indentation Testing
Controlled diamond point impacts create concentrated stress fields that induce micro cracking around the impression perimeter. Performing a vdi 3198 test allows quality inspectors to categorize coating adhesion from acceptable crack patterns to severe film delamination. Numerical classes HF1 through HF4 denote acceptable adhesion quality.
Tooling Durability
High adhesion strength prevents hard physical vapor deposition coatings from flaking off mold cores during high pressure injection cycles. Tool inserts meeting vdi 3198 requirements withstand abrasive wear from glass filled resins without coating delamination. Intact coatings lower friction forces during part ejection.
Adhesion integrity prevents premature tooling surface failure.
Substrate Boundary
Insufficient substrate hardness under thin coatings permits localized plastic deformation of underlying tool steel, invalidating test crack interpretations. Softer tool steels flex under indenter loads, causing premature coating failure regardless of actual bond strength. Standardized test protocols require strict substrate hardness verification prior to indentation.
Adherence to vdi 3198 rules ensures accurate coating bond evaluation.