Sapphire Crystal KY Grown Single Crystal Sapphire Manufacturer

One of our core manufacturing technologies is the Kyropoulos (KY) crystal growth method, one of the world's most advanced processes for producing large-diameter, high-quality sapphire crystals.

Unlike flame fusion or Verneuil methods, the KY process allows sapphire crystals to grow slowly under carefully controlled thermal conditions, minimizing internal stress and crystal defects. The result is a crystal with excellent optical homogeneity, low dislocation density, and outstanding mechanical properties.

KY Sapphire Growth Process

The manufacturing process typically includes:

1. High-Purity Raw Material Preparation
   • 99.99%–99.999% high-purity Al₂O₃ powder
   • Strict impurity control
   • Controlled atmosphere inside the furnace
2. Melting
   • Aluminum oxide is melted at approximately 2050°C inside a tungsten or molybdenum crucible.
3. Seed Crystal Introduction
   • A precisely oriented sapphire seed crystal (C-plane, A-plane, R-plane, M-plane, etc.) is dipped into the molten material.
4. Slow Crystal Growth
   • The crystal is grown over several days or weeks by carefully controlling temperature gradients and pulling rates.
   • Slow growth minimizes thermal stress and produces large single crystals with excellent structural integrity.
5. Controlled Cooling
   • After growth, the boule is cooled gradually to prevent cracking and residual stress.
6. Annealing
   • Internal stress is further relieved through heat treatment, improving optical and mechanical performance.
7. Orientation & Precision Machining
   • X-ray orientation
   • Diamond wire cutting
   • Grinding
   • Double-side polishing (DSP)
   • Optical polishing
   • Precision CNC machining