Why do molybdenum crucibles break during use?
Improper use: If the temperature drops too quickly during use, the stress caused by the temperature difference between the outer and inner walls exceeds the range that the crucible can withstand, which can also lead to fracture.
Can a molybdenum crucible be heated until it is red hot?
Yes, it is possible to heat a molybdenum crucible to red hot. Molybdenum has a high melting point of 2,623 degrees Celsius (4,753 degrees Fahrenheit), which allows it to withstand extremely high temperatures without melting. This makes molybdenum crucibles suitable for applications that require heating to red-hot temperatures, such as the melting of metals, glass, or other high-temperature processes. However, it is important to ensure that the crucible is used within its specified temperature range and that proper safety measures are followed when using red hot crucibles.
Why must you heat the crucible gently for the first minute?
It is important to heat the crucible gently during the first minute to prevent thermal shock. When a cold crucible is exposed to very high temperatures too quickly, it can cause uneven expansion and thermal stress, which can cause the crucible to crack or crack. Minimize the risk of thermal shock and ensure the integrity of the crucible during heating by heating the crucible gently at the beginning and gradually bringing it to the desired temperature. This approach helps extend the life of the crucible and maintains its structural integrity for reuse.