The Most Common Misunderstandings about Magnetic Particle Testing
When in doubt, always check with a certified Level III or contact your NDT product supplier.
Alfred V. de Forest and Foster B. Doane developed the magnetic testing method in the early 1930s and since then it has become a core method of nondestructive testing. Generations of NDT professionals have used this form of testing, and along the way, a handful of common misunderstandings have developed. This article explores these common and incorrect assumptions about magnetic particle inspection and how to combat these misunderstandings.
First and foremost, it is important to understand the composition of the parts being tested as not all metals are ferromagnetic and can be used in magnetic particle testing. Only iron, nickel, and cobalt can be magnetized. Most of their alloys and some forms of steel are also magnetic. Aluminum is used in an estimated 80% of aircraft materials today because it is lightweight, strong, predictable, and inexpensive. It is also one of the most common metals organizations attempt to test with magnetic particle inspection that cannot be magnetized.