Performance improvement of an automotive alternator by heat treatment

In this paper, heat treatment (HT) is proposed to maximize magnetic property recovering strain and stress due to recrystallization. To find the optimal point of HT, two HT are performed at two different temperatures. This HT study showed that both magnetization and core loss characteristics are greatly improved which enables application to alternator performance test. Two alternator models are fabricated with the HT stator cores and used for performance test showing 5% output increase and 0 .4% VDA efficiency improvement. Audible noise test is also performed to verify deterioration due to HT.