The electromagnet coilformer was analyzed by means of metallurgical microscope. The results shows that cracks results from excessive high temperature while casting and material embrittlement.
用金相显微镜对衔铁线圈骨架的裂纹进行分析。结果表明，由于锻造加热温度偏高， 材料脆化导致裂纹形成。
2
The MF voice coil is of copper-coated aluminium ribbon, expensively edge-wound over a polyimide former to increase sensitivity by maximising the amount of copper in the magnet gap.