A printed alloy lowers magnetic losses in laboratory measurements
A peer-reviewed materials experiment used binder jetting to produce an iron, cobalt, nickel and chromium alloy with low resistance to magnetic reversal and high electrical resistivity. Carbon entering the material during sintering helped limit eddy currents. Laboratory measurements show a balance useful for complex magnetic parts, but they do not establish energy savings in an operating motor.
Science··Midday
Powder and binder formed a complex magnetic part
Iron, cobalt, nickel and chromium were combined in a powder-built alloy investigated for soft-magnetic components, whose magnetization can reverse readily. Binder jetting forms the part before a high-temperature sintering step joins the material. The peer-reviewed experiment used laboratory specimens and a demonstration stator, the stationary component of a motor, to examine how that route affects magnetic behaviour. A complete motor was not tested for energy efficiency.[1]
Carbon released by the binder dissolved in the alloy during sintering. Electrical resistivity reached 146 microohm centimetres, over twice that of the cast comparison material, restricting eddy currents under changing magnetic fields. Large grains, low porosity and little residual stress accompanied easy magnetic reversal. Separate measurement arrangements gave coercivity values of 15 and about 30 amperes per metre; they describe different measurement conditions.[1]
Lower measured loss came with a magnetic trade-off
At a magnetic flux density of 1 tesla and frequency of 50 hertz, specific loss measured 1.62 watts per kilogram, against 2.05 for the iron–silicon benchmark. The alloy’s saturation flux density was about 1.4 tesla, slightly below the cast comparison. Dimensional shrinkage during sintering also matters for manufacturing. An accelerated 100-hour exposure at 200 °C found no substantial degradation, but did not establish service life.[1]
