What is Metallographic Grinding Test?

Metallographic grinding test is a testing method that involves cutting open and grinding the crimped terminals, then observing their internal structure under a microscope. This is used to confirm whether the copper wire and terminal metal are truly and tightly bonded, ensuring transmission efficiency. Because crimp quality cannot be seen from the outside, a good appearance does not necessarily mean there are no voids, loose parts, or broken wires inside, all of which can lead to poor contact, increased impedance, and overheating. Through metallographic analysis, we can determine whether the copper wire evenly fills the crimp groove, whether the crimp is full and solid, and whether there are any voids, etc. Metallography is a destructive test, usually performed during first-article inspection or periodic sampling inspections of high-reliability product processes to ensure that each batch meets the original manufacturer's or IPC WHMA 620 standards. In short, metallographic testing is like an "X-ray inspection" of crimp quality, allowing us to see the true internal conditions that cannot be seen from the outside, ensuring long-term stable and reliable signal transmission of the wiring harness.