Monthly Tech-Tip from Tony Hansen SignUp

No tracking! No ads!

200 mesh | 325 mesh | 3D Design | 3D Printer | 3D Printing Clay | 3D Slicer | 3D-Printing | Abrasion Ceramics | Acidic Oxides | Agglomeration | AI in Ceramics | Alkali | Alkaline Earths | Amorphous | Apparent porosity | Artware | Ball milling | Bamboo Glaze | Base Glaze | Base-Coat Dipping Glaze | Basic Oxides | Batch Recipe | Bisque | Bit Image | Black Core | Bleeding of colors | Blender Mixing | Blunging | Body Bloating | Body glaze Interface | Body Warping | Bone China | Borate | Boron Blue | Boron Frit | Borosilicate | Breaking Glaze | Brick Making | Brushing Glaze | Calcination | Calculated Thermal Expansion | Candling | Carbon Burnout | Carbon trap glazes | CAS Numbers | Casting-Jiggering | Catch Glaze | Celadon Glaze | Ceramic | Ceramic Binder | Ceramic Decals | Ceramic Glaze | Ceramic Glaze Defects | Ceramic Ink | Ceramic Material | Ceramic Oxide | Ceramic Slip | Ceramic Stain | Ceramic Tile | Ceramics | Characterization | Chemical Analysis | Chromaticity | Clay | Clay body | Clay Body Porosity | Clay Stiffness | Clays for Ovens and Heaters | Co-efficient of Thermal Expansion | Code Numbering | Coil pottery | Colloid | Colorant | Commercial hobby brushing glazes | Cone 1 | Cone 5 | Cone 6 | Cone plaque | Copper Red | Cordierite Ceramics | Crackle glaze | Cristobalite | Cristobalite Inversion | Crucible | Crystalline glazes | Crystallization | Cuerda Seca | Cutlery Marking | Decomposition | Deflocculation | Deoxylidration | Differential thermal analysis | Digitalfire Foresight | Digitalfire Insight | Digitalfire Reference Library | Dimpled glaze | Dip Glazing | Dipping Glaze | Dishwasher Safe | Dolomite Matte | Drop-and-Soak Firing | Drying Crack | Drying Performance | Drying Shrinkage | Dunting | Dust Pressing | Earthenware | Efflorescence | Encapsulated Stain | Engobe | | Fast Fire Glazes | Fat Glaze | Feldspar Glazes | Fining Agent | Firebrick | Fireclay | Fired Strength | Firing Schedule | Firing Shrinkage | Flameware | Flashing | Flocculation | Fluid Melt Glazes | Flux | Food Safe | Foot Ring | Forming Method | Formula Ratios | Formula Weight | Frit | Fritware | Functional | GHS Safety Data Sheets | Glass vs. Crystalline | Glass-Ceramic Glazes | Glaze Blisters | Glaze Bubbles | Glaze Chemistry | Glaze Compression | Glaze Crawling | Glaze Crazing | Glaze Durability | Glaze fit | Glaze Gelling | Glaze laydown | Glaze Layering | Glaze Mixing | Glaze Recipes | Glaze shivering | Glaze Shrinkage | Glaze thickness | Globally Harmonized Data Sheets | Glossy Glaze | Green Strength | Grog | Gunmetal glaze | High Temperature Glaze | Hot Pressing | Incised decoration | Industrial clay body | Ink Jet Printing | Inside-only Glazing | Insight-Live | Iron Red Glaze | Jasper Ware | Jiggering | Kaki | Kiln Controller | Kiln Firing | Kiln fumes | Kiln venting system | Kiln Wash | Kneading clay | Kovar Metal | Laminations | Leaching | Lead in Ceramic Glazes | Leather hard | Limit Formula | Limit Recipe | Liner Glaze | Liner glazing | Liquid Bright Colors | LOI | Low Temperature Glaze | Majolica | Marbling | Material Substitution | Matte Glaze | Maturity | Maximum Density | MDT | Mechanism | Medium Temperature Glaze | Melt Fluidity | Melting Temperature | Metal Oxides | Metallic Glazes | Micro Organisms | Microwave Safe | Mineral phase | Mineralogy | Mocha glazes | Mohs Hardness | Mole% | Monocottura | Mosaic Tile | Mottled | Mullite Crystals | Native Clay | Non Oxide Ceramics | Oil-spot glaze | Once fire glazing | Opacifier | Opacity | Ovenware | Overglaze | Oxidation Firing | Oxide Formula | Oxide Interaction | Oxide System | Particle orientation | Particle Size Distribution | Particle Sizes | PCE | Permeability | Phase Diagram | Phase Separation | Physical Testing | Pinholing | Plainsman Clays | Plaster Bat | Plaster table | Plasticine | Plasticity | Plucking | Porcelain | Porcelaineous Stoneware | Pour Glazing | Powder Processing | Precipitation | Primary Clay | Primitive Firing | Propane | Propeller Mixer | Pugmill | Pyroceramics | Pyrometric Cone | Quartz Inversion | Raku | Reactive Glazes | Reduction Firing | Reduction Speckle | Refiring Ceramics | Refractory | Refractory Ceramic Coatings | Representative Sample | Restaurant Ware | Rheology | Rutile Blue Glazes | Salt firing | Sanitary ware | Sculpture | Secondary Clay | Shino Glazes | Sieve | Sieve Shaker | Silica:Alumina Ratio | Silk screen printing | Sintering | Slaking | Slip Casting | Slip Trailing | Slipware | Slurry | Slurry Processing | Slurry Up | Soaking | Soluble colors | Soluble Salts | Specific gravity | Splitting | Spray Glazing | Stain Medium | Stoneware | Stull Chart | Sulfate Scum | Sulfates | Surface Area | Surface Tension | Suspension | Tapper Clay | Tenmoku | Terra Cotta | Terra Sigilatta | Test Kiln | Theoretical Material | Thermal Conductivity | Thermal shock | Thermocouple | Thixotropy | Throwing | Tony Hansen | Toxicity | Trafficking | Translucency | Transparent Glazes | Triaxial Glaze Blending | Ultimate Particles | Underglaze | Unity Formula | Upwork | Variegation | Viscosity | Vitreous | Vitrification | Volatiles | Water in Ceramics | Water Smoking | Water Solubility | Wedging | Whiteware | Wood Ash Glaze | Wood Firing | Zero3 | Zero4 | Zeta Potential

Eutectic

In ceramics, this term refers to certain chemistries that melt at much-lower-than-expected temperatures.

Key phrases linking here: eutectic - Learn more

Details

The lowest temperature at which a simple mix of oxides will melt and react to form a transparent glass. Mixtures of SiO2 and the alkalis and alkaline earth oxides are well studied. The temperature at which melting occurs is often an anomaly, that is, it is lower than the melting temperatures of similar mixtures. Lead-tin solder is an example. Lead melts at 327C, tin at 231C. The lowest melting combination is 67 lead, 33 tin (180C).

Generally, eutectics are a matter of academic study, reliance on them is not something designed into ceramic glazes. In fact, the opposite, non-eutectic mixtures, are the rule. All ceramic frits we know of behave in a non-eutectic way, most having a wide melting (or softening) range. This softening phenomenon is beneficial, it is what makes melting glazes hang onto the ware over a wide range of temperature (many must be heated well past the softening range to get mobile melts). Thus, being armed with a carefully calculated recipe to produce a eutectic at a specific temperature does not likely equip one to produce a better transparent base glaze than just using frits. This is because frits have a fundamental advantage: They have been premelted. That fact alone would likely trump the eutectic mix-of-materials (especially if the powder mix is not ball milled well to maximize particle surface area). The frit approach also has the advantage that gases of decomposition have already been expelled, creating a better potential for a transparent glass.

An novel method of glaze chemistry is promoted by Bob Magnuson (see link below). He explains how, in eutectic mixtures, all species solidify simultaneously to a clear glass, whereas in non-eutectic ones, excess or uninvolved oxides precipitate and solidify out-of-step. He demonstrates how knowing about eutectics makes it possible to formulate more transparent glazes and addresses the concepts of "combining eutectics" to build better transparent glazes. But the most exciting concept is mathematically subtracting eutectics from the unity molecular formula of stoneware glazes to isolate their mechanisms, or unique characteristics.

We have linked some eutectic mixtures, however these are not verified by any testing we have done. If this area is of interest to you it might be better to seek other sources of information (e.g. phase diagrams).

Related Information

Links

URLs http://en.wikipedia.org/wiki/Eutectic
Eutectic at Wikipedia
URLs https://ceramicartsnetwork.org/ceramics-monthly/ceramic-glaze-recipes/glaze-chemistry/techno-file-using-eutectics/#
Using Eutectics article and calculation workship by Bob Magnuson
URLs https://www.youtube.com/watch?v=FVUuhjnjAoA
German potter Cornelius Breymann investigates limit formulas, eutectics
Materials Sodium Metasilicate Eutectic
Materials Na & Sr Metasilicate Eutectic
Materials Na & Ba Metasilicate Eutectic
Materials Na & Ca Metasilicate Eutectic
Materials Ca Fluoride & Ca Metasilicate Eutectic
Materials Zinc and Cadmium Metasilicate Eutectic
Materials Eutectics
Typecodes Eutectic
These are theoretical mixtures of oxides, not real materials. Use these to learn about low melting chemistries.
By Tony Hansen
Follow me on

Got a Question?

Buy me a coffee and we can talk



https://digitalfire.com, All Rights Reserved
Privacy Policy