Sapphire Single Crystal Growing Tungsten Crucible Thermal Stress Analysis
- Details
- Category: Tungsten Information
- Published on Friday, 19 February 2016 17:15
Sapphire single crystal is kind of alumina (Al2O3) single crystal and its optical penetration is very wide. From near ultraviolet (190nm) to mid-infrared light it has very good transmission. On the other hand, due to its excellent optical properties, mechanical properties and chemical stability, and high strength, hardness, corrosion resistance, it is widely used in military, medical, electronics and other fields. And to produce excellent performance sapphire single crystal the crucible of sapphire single crystal growth furnace is a critical factor. With high purity, high density, crack-free, precise size, smooth inner and outer walls and other good features of the crucible for sapphire crystal seeding success rate in growth process, pulling quality control, de-crystal stick pan and extended service life has played a key role. Tungsten crucibles with high strength, high hardness and high temperature and other good performances are widely used in the sapphire growth furnace. The experiment found that the thermal stress concentration phenomenon in the sapphire single crystal growth process leads to short life of tungsten crucible. So many scientists after analyzed tungsten crucible failure factors in sapphire single crystal growth process found that thermal stress is the main reason for the failure of tungsten crucible.
Thermal stress: tungsten crucible in the course of using has suffered a long-term cyclical heating and cooling, leading to the crucible axial and radial exists temperature gradients. Besides, in the process of crystal growth will generate cycling thermal impact shock making crucible to generate microcracks. In the long-term recycling process, the microcracks will continue to expand, after reaching a certain level, resulting in the crucible scrapped.
The experiment found that the maximum thermal stress exists in the junction between crucible and the tray, to meet the crystal growth conditions, slowing the rate of temperature increase, smaller temperature gradient controlling, increasing the hole of the pressure pin, changing material of tray and pressure pin and other methods can reduce the thermal stress.
| Tungsten Supplier: Chinatungsten Online www.chinatungsten.com | Tel.: 86 592 5129696; Fax: 86 592 5129797;Email:sales@chinatungsten.com |
| Tungsten News & Prices, 3G Version: http://3g.chinatungsten.com | Molybdenum News & Molybdenum Price: http://news.molybdenum.com.cn |
sales@chinatungsten.com
闽公网安备 35020602000140号