XYXC can produce tungsten crystal seed holders and molybdenum crystal seed holders per customer’s specifications and drawings.

Physical and Mechanical Properties of Tungsten and Molybdenum Seed Holders:

Type	Purity	Density	Vapor (2100℃)	Coefficient ofThermal  Expansion (0-1600℃)	Recrystallization  Temperature
W	≥99.95%	≥19.2g/cm3	10-6Pa	4.98x10-6	~1350℃
Mo	≥99.95%	≥10.2g/cm3	10-2Pa	6x10-6	~1050℃

Quality Control:

- W & Mo rods must pass the ultrasonic and eddy current flaw inspection before manufacturing seed holder.

-100% quality check of the final products before packaging and delivering to the customers.

Storage & Usage Recommendations:

- Seed Holder must be stored in a dry area (humidity less than 60%),otherwise it is easy to be oxidized.

- After first round, seed holder, whether it is tungsten or molybdenum material, become brittle due to the complete recrystallization and need to be careful during the subsequent usage to avoid fracture. 

- Even though tungsten seed holder has better performance in high temperature environment than molybdenum seed holder. Both seed holders become brittle after recrystallization . Recommend to use ceriated tungsten seed holder if possible.