玻璃轉(zhuǎn)變及晶化的影響
( 華中科技大學(xué) 材料科學(xué)與技術(shù)系， 武漢 430074)
摘 要: 采用示差掃描量熱（DSC）分析方法， 測(cè)定了大塊非晶合金Pd-40Cu-30Ni-10P-20經(jīng)523K（（T-g-100K）<T<T-g）不同時(shí)間（0~64h）預(yù)退火后的玻璃轉(zhuǎn)變溫度T-g、 玻璃轉(zhuǎn)變峰溫度/T/-M、 起始晶化溫度T-x、 晶化峰的峰溫T-p、 晶化焓以及在玻璃轉(zhuǎn)變過(guò)程中的比熱容增量， 并根據(jù)Kissinger公式計(jì)算了晶化的表觀活化能。同時(shí)， 測(cè)量了不同時(shí)間預(yù)退火后樣品的顯微硬度。 結(jié)果表明： 在玻璃轉(zhuǎn)變溫度以下的預(yù)退火處理使Pd-40Cu-30Ni-10P-20大塊非晶合金的微觀原子組態(tài)發(fā)生變化，從而影響了其隨后的玻璃轉(zhuǎn)變行為， 但對(duì)晶化的影響不大。 其顯微硬度隨預(yù)退火時(shí)間的延長(zhǎng)而逐步增加后趨于穩(wěn)定。 并利用結(jié)構(gòu)弛豫理論分析了預(yù)退火對(duì)玻璃轉(zhuǎn)變、 晶化和顯微硬度的影響。
關(guān)鍵字: 大塊非晶合金; 結(jié)構(gòu)弛豫; 玻璃轉(zhuǎn)變; 晶化
crystallization of Pd-40Cu-30Ni-10P-20
（ Department of Materials Science and Technology,
Huazhong University of Science and Technology, Wuhan 430074, China）
Abstract: Differential scanning calorimeter(DSC) was used to investigate the specific heat difference, glass transition temperature, onset crystallization temperature, and their corresponding peak temperature, respectively, around glass transition region and crystallization enthalpy for Pd-40Cu-30Ni-10P-20 bulk amorphous alloys pre-annealed at 523K for different times (0-64 h). The apparent activation energies for crystallization were calculated by Kissinger equation. The micro-hardness of pre-annealed amorphous state was also measured. It is found that the glass transition behavior of Pd-40Cu-30Ni-10P-20 bulk amorphous alloy is influenced significantly due to atomic coorperation re-arrangement as a result of pre-annealing below glass transition temperature. The crystallization, however, seems to have no relation to pre-annealing time when pre-annealing temperature is 523K. In addition, the micro-hardness tends to level off after a steady rise with increasing of pre-annealing time. The effects of pre-annealing time on glass transition, crystallization and micro-hardness of Pd-40Cu-30Ni-10P-20 bulk amorphous alloy were discussed in terms of theory of structural relaxation.
Key words: bulk amorphous alloy; structural relaxation; glass transition; crystallization
