机械合金化法制备Co-Zr非晶软磁合金粉末的研究

Investigation of preparation of Co-Zr amorphous soft magnetic alloy powders by mechanical alloying

研究了Co Zr二元相图上4个共晶点成分配方 Co90 Zr10、Co53 Zr47、Co35 Zr65 和 Co21 Zr79 在球磨条件下的非晶态合金形成能力.分析结果表明,4种配方在一定的球磨时间内都能形成非晶态合金,非晶形成时间由短到长的合金组分依次为Co35Zr65、Co21Zr79、Co90Zr10和Co53Zr47,其中非晶形成能力最强的是 Co35 Zr65.作为选择非晶态合金成分的判据来说,对于机械合金化法(MA)法,Davies的共晶线准则比较合适.但若球磨时间继续延长,No.3 特别是No.4样品球磨产物中出现明显的纳米微晶CoZr2 金属间化合物.说明Co Zr合金系随着 w(Zr)的增加,金属间化合物形成能力增加,这与Co和Zr的晶体结构有关.球磨时间对非晶的形成有重要影响,球磨时间过长,使形成的非晶态合金反而向晶体转化.

The glass forming ability of four eutectic compositions such as Co_(90)Zr_(10),Co_(53)Zr_(47),Co_(35)Zr_(65),and Co_(21)Zr_(79) on Co-Zr phase diagram is studied under ball grinding conditions. X-ray diffraction (XRD) results show that all these alloys can form amorphous alloys within a definite milling period.The milling time is in increasing order for these alloys in order as Co_(35)Zr_(65),Co_(21)Zr_(79),Co_(90)Zr_(10) and Co_(53)Zr_(47) .Co_(35)Zr_(65) alloy play the best GFA among these four alloys.As for the criterion of selection of composition of amorphous alloys,the criterion of eutectic line of Davies is relatively suitable to form amorphous when MA method is used.If the milling time is,however,lengthened further,specimen No.3,especially No.4 would results in appearance of obvious nanometer microcrystalline CoZr_2 intermetallic compound within its ball-milling resultant,indicating that Co-Zr alloy system increases the formation ability of intermetallic compound with the content of Zr,and this is related to the crystal structure of Co and Zr.The milling time plays an important role in formation of Co-Zr amorphous alloys. If the milling time is too long,the formed amorphous alloys will turn into crystalline instead.