Determining the optimal sintering time after magnesium oxide refilling requires considering the holding temperature, material properties, and performance test results. It is typically 1–2 hours. This time is sufficient to ensure sufficient recrystallization of the magnesium oxide grains, forming a dense and stable insulating structure.
1. Based on the Matching of Temperature and Material Properties
|
Material Type |
Recommended Holding Time |
Explanation |
|
High-purity magnesium oxide (≥99.9%) |
1–1.5 hours |
Low impurities, high activity, fast recrystallization |
|
Nanoscale or ultrafine powder |
1 hour |
Large specific surface area, easy to sinter, avoids over-burning |
|
Conventional electrical grade (100–200 mesh) |
1.5–2 hours |
Requires longer holding time to ensure density and uniformity |
In practice, holding at 900℃ for 1.5 hours is the standard process for most compliant manufacturers (such as Liaoning Jiashun Technology).
2. Verification through small-batch gradient testing: It is recommended to conduct test firings at three time intervals: 1 hour, 1.5 hours, and 2 hours, with 3 samples per group. Test the following key indicators:
Cold insulation resistance (≥500 MΩ)
Withstand voltage performance (AC 2000V, no breakdown after 1 minute)
Resistance after hot and humid conditions (≥200 MΩ)
Result analysis: Select the time point with the most stable data and no breakdown flashover as the optimal parameter to avoid performance degradation due to insufficient time.
3.Compliance with industry standards and practices: HG/T 6445-2025 stipulates that the sintering holding time shall not be less than 1 hour, and a complete thermal control curve record must be provided.
Compliant service providers such as Liaoning Jiashun Technology and Dashiqiao Meier Magnesium Products use 1.5 hours as the standard process duration.
In high-requirement scenarios such as injection molding and medical applications, 1.5–2 hours should be prioritized to ensure long-term reliability.
If the time is less than 1 hour, it is easy to cause incomplete recrystallization and loose insulation structure; if it is too long, it may lead to increased energy consumption and material aging risk.
