PVD Vacuum Coating Process and Materials for Metal Artificial Teeth

PVD Vacuum Coating Process and Materials for Metal Artificial Teeth

一、Core Materials

1. Substrate Materials (Metal Artificial Tooth Bases)

2. Coating Materials (PVD Deposition Layers)

3. Auxiliary Materials

• Process Gases: High-purity argon (Ar, 99.999%+ for sputtering/cleaning), nitrogen (N₂, for nitride formation)
• Cleaning Agents: Alkaline degreasing solution (5-10% concentration), anhydrous ethanol, hydroxyapatite 研磨 powder (0.5μm/40μm)
• Target Materials: Titanium (Ti) targets, titanium-aluminum (Ti-Al) alloy targets, graphite targets (for DLC)

二、Standard Coating Process (PVD Vacuum Coating Machine)

Stage 1: Pre-Treatment (Critical for Adhesion)

• Mechanical Cleaning
  • Ultrasonic cleaning: 20-30 minutes in alkaline solution (60-80℃) to remove oil/contaminants
  • Surface grinding: Manual polishing with 0.5μm hydroxyapatite powder, followed by ultrasonic grinding in ethanol suspension (40μm HA powder) for 20 minutes
  • Drying: 10-20 minutes at 60-80℃ to eliminate residual moisture (surface tension: 30-50 mN/m)

• Chemical Activation
  • Acidic etching (for Co-Cr alloys): Dilute hydrochloric acid solution to create micro-rough surface
  • Passivation: Nitric acid solution (pH 2-4) to form dense oxide film, enhancing corrosion resistance

• Plasma Cleaning
  • Argon glow discharge in vacuum chamber (10⁻² Pa)
  • High-energy ion bombardment to remove nanoscale oxides and activate surface atoms

Stage 2: Vacuum Environment Establishment

• Dual-Stage Evacuation
  • Rough pumping: Mechanical pump reduces pressure to <10 Pa
  • Fine pumping: Turbomolecular pump + titanium sublimation pump to reach 10⁻³~10⁻⁴ Pa (ultra-high vacuum)

• Gas Purification
  • Low-temperature cold trap (-120℃) removes moisture
  • Zirconium-aluminum getter purifies process gases to 99.999%+ purity

Stage 3: Coating Deposition (Key Process Control)

Stage 4: Post-Treatment & Quality Inspection

• Vacuum Annealing
  • Temperature: 300-400℃; Holding time: 1-2 hours
  • Eliminates internal stress and improves coating crystallinity

• Performance Testing
  • Adhesion: Cross-cut test (ASTM D3359, 5B grade) or Rockwell indentation (HF1 grade)
  • Corrosion resistance: Neutral salt spray test (NSS, 500 hours no rust)
  • Surface Quality: Ra ≤0.05 μm (profilometer measurement); Color stability (ΔE .7 after 34 days NaCl immersion)

• Final Finishing
  • Precision polishing to adjust occlusion fit
  • Ultrasonic cleaning to remove post-processing residues

（注：文档部分内容可能由 AI 生成）