Aluminum Melt Thermowell

Five Material Options for Aluminum Service

We offer this aluminum melt thermowell in five different materials for 660-780℃ aluminum temperature measurement. Aluminum is very reactive. It dissolves most metals and reacts with ordinary ceramics. It also sticks to surfaces easily. Our 21 years of experience in thermowell manufacturing have taught us which materials work best. We produce this product in silicon nitride, Sialon, silicon carbide, 99 alumina, and metal types. Each material serves a different purpose. Silicon nitride is the top choice because it does not wet with aluminum at all. Sialon is an upgraded version with higher hardness for automated casting lines. Silicon carbide works for short-term use but reacts with aluminum over time. 99 alumina is low-cost but has poor thermal shock resistance. Metal types like 310S dissolve fast in aluminum and should never be used for long immersion.

Table A – Top Performers for Aluminum Immersion

Table B – Alternative Materials (Limited Use)

Choose the Right Grade for Your Furnace

This aluminum melt thermowell gives you the flexibility to match your exact operating conditions. Silicon nitride is the standard for 24/7 continuous melting furnaces and die-casting machine pools. It lasts 6-12 months without sticking or degrading. Sialon extends that life to 8-14 months, making it ideal for high-speed automated production lines with frequent probe lifting. Silicon carbide handles high temperatures up to 1600℃ but should not stay in aluminum for more than 1-3 months. It reacts with aluminum to form brittle compounds. 99 alumina is the cheapest choice but cracks easily from cold insertion. You must preheat it before each use. Metal materials like 310S and Inconel are only for furnace gas temperature measurement. Never put any metal product into liquid aluminum. It will dissolve in days and contaminate your melt.

Custom Manufacturing and Safe Use

We custom-make this aluminum melt thermowell in various diameters, lengths, and mounting styles. Silicon nitride and Sialon products need special sintering, so custom samples take 15 to 30 days. Silicon carbide and alumina take 10 to 20 days. We recommend you tell us your full operating conditions: continuous or intermittent immersion, melt temperature, and how often you lift the probe. Our team gives professional material recommendations based on your specific needs. Every product gets foam-lined packaging for safe shipping. We support EXW, FOB, and DDP terms. Payment is 30% deposit and 70% before shipping. For safety, always dry your aluminum melt thermowell completely before inserting it into hot aluminum. Wet ceramic tubes can cause steam explosions. This is a serious safety risk. Also avoid hard impacts that can create cracks in ceramic materials.