NEWS

Low Pressure Die Casting Mold Surface Treatment & Release Agent Application Standard: Xinfeng Mould Tooling Specification

  • Browse number: ...
  • Release time: 2026-09-29

Low Pressure Die Casting Mold Surface Treatment & Release Agent Application Standard: Xinfeng Mould Tooling Specification

Standardized LPDC mold surface treatment and release agent application directly reduce soldering and surface defects. Improper coating and surface treatment increases mold soldering failure rate by 33% within 1 year. This article sorts out surface finishing, nitriding rules, release agent selection and on-site operation specifications for aluminum alloy casting molds.

All mold cavity surfaces after CNC finishing must be polished to Ra0.8 μm before nitriding. Rough surface above Ra1.6 μm reduces nitriding layer adhesion by 36% and accelerates peeling.

Nitriding temperature controlled at 510–540℃ to form uniform compound layer. Temperature over 550℃ causes grain coarsening and reduces substrate toughness by 27%.

Nitriding layer thickness target 0.08–0.12 mm. Layer less than 0.08 mm cannot resist aluminum soldering; layer thicker than 0.12 mm easily peels under thermal cycling.

Post-nitriding fine polishing removes surface brittle compound layer, reducing aluminum soldering tendency by 40%.

Release agent types are classified according to casting wall thickness. Water-based release agent for thin-wall parts below 4 mm; semi-water-based release agent for thick structural bosses.

Release agent coating thickness controlled at 0.2–0.3 mm. Over-spray forms thick insulating layer, slows solidification and extends casting cycle by 18%. Insufficient coating leads to soldering and part sticking.

Spraying gun pressure kept at 0.3–0.5 MPa, spraying distance 180–240 mm for uniform coating. Uneven spraying creates local thick/thin coating and inconsistent surface quality.

Mold surface must be fully dried after spraying. Residual moisture on cavity surface generates hydrogen gas and forms pinholes on casting surface.

Aluminum soldering on cavity surface needs mechanical cleaning and local polishing; heavy soldering damage requires re-nitriding treatment.

Mold surface protection for long-term storage: clean cavity, apply anti-rust oil and seal packaging when ambient humidity >65% RH.

Surface inspection every 5000 casting cycles, check nitriding layer condition, surface roughness and soldering status.

FAQ

Q1: What surface roughness required before LPDC mold nitriding? A1: Cavity surface polishing to Ra0.8 μm is mandatory before nitriding treatment. Q2: What is standard nitriding layer thickness for LPDC mold surface? A2: 0.08–0.12 mm nitriding layer balances wear resistance and thermal fatigue performance. Q3: What is the qualified thickness of release agent coating? A3: Release agent coating thickness should be maintained between 0.2 mm and 0.3 mm.

url: https://zj-xinfeng.com/news/1068.html