| The current commercial amorphous alloy（1K101）developed in 1970s by the United States Honeywell company,exhibits excellent soft-magnetic properties.Howere,it also has many disadvantages,such as lower Bs of 1.56 T compared with the traditional Si steel of 1.8-1.9 T.The amorphous ribbons also change into brittleness after stress annealing.After decades of development,Hitachi company developed Metglas2605HB1 in 2005.The addition of C improve the Bs to 1.64 T.In this paper,Fe（Co,Ni）SiBPC amorphous alloys with high saturation induction,good soft magnetic properties,and good bending toughness after annealing were developed.The results are as follows:Fe82.7-85.7Si2-4.9B9.2-11.2P1.5-2.7C0.8 soft magnetic amorphous alloys with adistinctly high Fe content of 93.5-95.5 wt.%were prepared by component design and composition adjustment.All alloys can be readily fabricated into completely amorphous ribbon samples with good surface quality by the single copper roller melt-spinning method.These alloys show a good bending ductility and excellent magnetic properties after annealing,i.e.,a lowcoercivity of 3.3-5.9 A/m,high permeability of 5000-10000 and high flux saturation density of 1.63-1.66 T.The mechanism of the good amorphous forming ability and soft-magnetic properties are explored.The amorphous alloys with the high Fe content comparable with that of the desired high Si alloy are promising candidates for the potential application in electric devices.For further increase the Bs,Fe83（Cox,Niy）(B11Si2P3C1)1-x,y/17（x,y=1-3）amorphous alloys with excellent soft-magnetic properties were developed and then the microalloying and cluster effects were explored.The microalloying of Co and Ni improves the Bs from 1.65 T to 1.67-1.72 T and 1.66-1.68 T,respectively.The Ni-doped alloys exhibit better soft-magnetic properties,containing low Hc of about 5.0 A/m and highμe of（8-10）×103,while the microalloying of Co leads to a deteriorative Hc of 5.0-13.0 A/m andμe of（5-8）×103.Moreover,microalloying of Ni can increases the ductile-brittle transition（DBT）temperature of the ribbons,while the totally opposite effect is found in the Co-doped alloys.The formation of denseα-Fe（Co,Ni）clusters during annealing process is used to explain the distinct effects of Co and Ni microalloying on the magnetic properties and bending toughness.The magnetic domains of high Fe-content amorphous alloys were also studied.From the change of magnetic domain,it can be seen that the magnetic domain walls can be movement and rotation in the magnetic field.At low field,the domain walls change mainly by moving,while at high filed,the domain walls change mainly by rotation.Amorphous alloys with high iron content are easy to form clusters during heat treatment.These clusters can not be recognized by XRD,while they have great influence on the properties of the ribbons.With the increase of Fe-content of amorphous alloy,the amorphous forming ability reduce,which make it easy to form more clusters during heat treatment.That is the reason 180°domains change into stripe domains with the increase of Fe content.In this paper,a series of high Bs amorphous alloys were prepared.These amorphous alloys with a higher Fe content are promising candidates for potential applications in electric and magnetic devices. |
