Laser gauge. Dimensional inspection. Coordinate Measuring Machine (CMM). X-ray technology. 3D “blue light” digitizing scanner. How do these inspection methods differ and which one or combination, is most appropriate for providing the desired data? The criteria for choosing the inspection method for verifying the dimensional integrity of a ceramic core used in investment casting can be as varied as the cores themselves.
Every core design is different in shape, size and complexity. There are so many variables in determining the inspection method, and because the different methods produce different information, the best place to start would be to determine the critical data that is required.
As an engineer, you may be interested in verifying the casting wall thickness where another engineer may be more concerned with the dimensional measurement of the length of a core. The critical information being sought by one customer may be entirely different for the next. Core-Tech prides itself on being responsive and flexible in meeting our customer’s individual needs, we are also happy to work with each engineer in helping to determine the critical data that is needed and how that information can be best ascertained.
Another factor that plays a central role in the inspection process is tolerance.
Again, tolerance can be a subjective measurement depending on the complexity of the core, and the customer’s needs. Additionally, as tooling begins to wear, adjustments may need to be made to retain tolerance allowances, so the life of the tooling becomes a factor in the inspection results as well.
Once the required inspection data is determined, Core-Tech and our customer can begin to determine the most appropriate method of inspection. The latest technology offered in the 3D “blue light” method is the most thorough method of inspection, yet X-ray technology offers something that the 3-dimensional scanning does not––a look inside the core to verify the internal integrity of the core.
Core-Tech was one of the first core producers to utilize X-ray technology for inspection and continues that tradition with being the first core producer to now employ the “blue light” technology. Both of these inspection methods can be utilized for inspecting cores at a very comprehensive level.
Other choices for core inspection includes the Coordinate Measuring Machine (CMM). This device measures the geometry of cores by sensingdiscrete points on the surface of the core with a probe. Incidentally, some customers require 100% of their product is inspected using this method. The CMM machine can be programmed with as few or as many points as needed, depending on the nature of the core geometry. Similar in concept to the CMM is laser gauge inspection method which uses a laser to measure predetermined points on the ceramic core. Both of these inspection methods require fixturing or nests, adding to the cost of this inspection method, whereas blue light and X-ray do not.
Choosing the most appropriate inspection method for your cores can seem like a daunting task, however with assistance from the knowledgeable staff at Core-Tech, the inspection process doesn’t have to be confusing or overwhelming.