Component Testing for Tier 1 Automotive Suppliers
By Jesse Herrin, Zetec Product Manager – Eddy Current Systems
In an industry known for managing quality, automotive component suppliers have few clear guidelines when it comes to nondestructive testing. Most Tier 1 suppliers inspect heat-treated materials and finished components as part of their internal quality controls, but supplier agreements can be vague and there are virtually no industry standards when it comes to NDT.
As a result, there can be big variations in knowledge and capabilities among suppliers.
In general, nondestructive testing occurs at two points in the production process: the first is to verify whether the manufacturer has been supplied with the proper grade of steel; the second is after heat treatment to ensure that the microstructure is sound and there are no defects that would lead to a rejected part.
Eddy current testing is a common technique for detecting surface and sub-surface defects and metallurgical qualities in conductive materials. It is used to inspect for surface cracks, hardness, inclusions, grinding burns, case depth, and other material defects, as well as the quality of welds and seams.
In high-volume automotive component manufacturing, eddy current inspection instruments like Zetec’s InSite system can be automated and incorporated into the production line, typically right after heat treatment.
A machine picks up the part, moves it into the test position, brings the coil down on the part or lifts the part onto the coil and sends the signal to the instrument with no variation from one inspection to the next. Once the test is complete, there’s a determination of “accept” or “reject” and then the part goes down the appropriate chute.
In-line eddy current inspections are fast, clean, keep the line moving and they have the benefit of consistency. Probes can be customized to the shape of a component—imagine a probe that nestles into the teeth of a spline shaft, for example—allowing the eddy current coils to stay close and nominally perpendicular to the material.
As a result, every part produced is subjected to the same standard test, regardless of which machine did the heat treating or which operator is running the equipment.
Handheld Tools
For lower production volumes, the latest generation of handheld eddy current instruments like Zetec’s MIZ-21C have the processing power, software, and battery life to perform inspections virtually anywhere, with C-Scan capability that provides real-time visual feedback to the technician and production crew.
Probes like Zetec’s Surf-X array probe with flexible surfaces allow the eddy current coils to stay close and nominally perpendicular to the material, even when that surface is rough or the geometry is complex.
Portable eddy current instruments are easy for an operator to handle, and they generate a valuable digital record of inspection that can be stored, analyzed and compared against a history of results. They’re ideal for low production runs or whenever you need to stop and take a closer look at a part or piece without having to destroy it or take extra steps to prepare the surface for testing.
Whether the inspection is incorporated into the production line or takes place at a bench top with a handheld instrument and probe, eddy current technology continues to evolve in ways that produce inspections that are quick to set up and complete. Given the full range of techniques available, eddy current can strike the right balance of inspection speed, detection capability, and cost effectiveness—without having to destroy the piece you’re testing.
Zetec is a global leader in nondestructive testing (NDT) solutions for the critical inspection needs of industries the world counts on every day. To learn more, contact Zetec today!