A summary of the 2019 Blasch paper that continues the stress analysis of ceramic core setters and asks what it costs to get them wrong.
The first paper asked where a setter is stressed.
The second asks what the firing conditions cost the plant.
This Blasch white paper from 2019 extends the earlier stress analysis of ceramic core setters for aerospace and industrial gas turbine (IGT) castings. It looks at the thermal conditions a setter sees during core firing and at how setter design and material can lower the process costs that come from setters that slump, crack or have to be replaced early.
| Item | Detail |
|---|---|
| Title | Improving Thermal Conditions and Reducing Process Costs for Core Setters in Aerospace and IGT Applications |
| Type | White paper, presented at the 66th Investment Casting Institute Technical Conference, October 2019 |
| Authors | Phil Geers, Senior Market Manager Molten Metals; William Russell; Dave Bacchi, Blasch Precision Ceramics |
A core setter is not part of the casting, but it decides whether the core that goes into the shell is the core that was designed. Every setter that deforms or cracks costs twice: once as a replacement part and once as cores that are out of tolerance, found only further down the casting line.
Blades and vanes for aerospace engines and industrial gas turbines carry complex cores, and the plants that make them are pushed to fire faster. Faster heat up and cool down means more thermal shock on the setter in every cycle.
The 2018 paper used finite element analysis to compare stresses in a setter in different orientations and to find the orientation with the lowest stress. The 2019 paper takes that analysis further, toward the thermal conditions in firing and the cost side of the process, as the title says.
The detailed findings, figures and any cost estimates are in the full paper, which is available on request.
The setter with the lower price is not the cheaper one if it changes shape before the cores it carries do.
Three questions decide whether a setter is a cost line or a non issue:
Blasch casts ceramic core setters with geometry that follows the core, to tight tolerances and in several high purity grades, and tests strength, density, thermal shock and creep deflection in its own laboratory. The first core setter paper explains the stress analysis this work starts from, and the molten metals overview shows the other parts Blasch makes for investment casting plants.
Industrial gas turbines. Their blades and vanes are investment cast with ceramic cores, as in aerospace, often at larger sizes.
No. The figures are in the full paper. Request it and a Blasch engineer sends it with the earlier paper.
The 2018 paper analyzes stresses and setter orientation. The 2019 paper continues that work toward firing conditions and process costs.
Modulus of rupture, Archimedes density, thermal shock resistance, creep deflection, corrosion and wear resistance, in the Blasch laboratory in Albany.
Send the core type, the firing cycle and how often setters are replaced. A Blasch engineer reviews material, geometry and orientation.
