發(fā)布時間：2018-04-09 15:53

  本文選題：金屬玻璃　切入點：溫度場　出處：《沈陽工業(yè)大學(xué)》2017年碩士論文

【摘要】：不同于晶態(tài)合金的凝固過程,金屬玻璃由于冷卻速度快、熔體原子來不及擴散重排,凝固過程中不產(chǎn)生結(jié)晶現(xiàn)象。其整個凝固過程中沒有潛熱釋放,凝固降溫曲線中不出現(xiàn)平臺。由于金屬玻璃凝固過程中這種潛熱消失的機制尚不明確,因此,有必要對金屬玻璃的凝固規(guī)律進行探究。本文采用水冷淬火和銅模鑄造兩種方式制備了Zr_(41)Ti_(14)Ni_(10)Cu_(12.5)Be_(22.5)塊體金屬玻璃,利用EM9104C多路數(shù)據(jù)采集儀對其凝固過程進行了溫度場數(shù)據(jù)采集。在所得溫度數(shù)據(jù)的基礎(chǔ)上,對合金與不同傳熱介質(zhì)間的界面換熱系數(shù)進行了推導(dǎo)計算,給出了液固界面推進速度在不同坐標(biāo)系中的表達式。同時利用ProCAST數(shù)值模擬軟件模擬了Zr_(41)Ti_(14)Ni_(10)Cu_(12.5)Be_(22.5)塊體金屬玻璃的銅模冷卻凝固過程,并預(yù)測了最大理論制備直徑。計算與模擬結(jié)果表明:水淬法制備直徑為16mm的Zr_(41)Ti_(14)Ni_(10)Cu_(12.5)Be_(22.5)塊體金屬玻璃時,合金表面溫度從920℃冷卻至100℃需要的時間為26.5s,通過有限差分方程計算得到的合金與石英管間界面換熱系數(shù)平均值約為1300W/(m2?K)。改用銅模澆鑄制備Zr_(41)Ti_(14)Ni_(10)Cu_(12.5)Be_(22.5)塊體金屬玻璃時,合金與銅模間的界面換熱系數(shù)隨合金溫度的升高而增大,但不是線性比例關(guān)系。直徑8mm的Zr_(41)Ti_(14)Ni_(10)Cu_(12.5)Be_(22.5)塊體金屬玻璃冷卻速度曲線模擬結(jié)果與實測值基本吻合。在澆注溫度為840℃時,使用銅�？芍苽涞腪r_(41)Ti_(14)Ni_(10)Cu_(12.5)Be_(22.5)塊體金屬玻璃最大理論直徑尺寸約為125~130mm。水淬法制備金屬玻璃在溫度場測量方面存在較大局限性,對探究金屬玻璃凝固過程的研究不適用。相比于晶化凝固方式,合金熔體按非晶方式凝固時,合金比熱容在玻璃轉(zhuǎn)變點附近存在著階躍臺階,而潛熱的消失與這種比熱的變化有一定關(guān)聯(lián)。
[Abstract]:Different from the solidification process of the crystalline alloy, due to the rapid cooling rate, the melt atoms do not have the diffusion and rearrangement, and the crystallization does not occur during the solidification process.There is no latent heat release in the whole solidification process, and no platform appears in the solidification cooling curve.Since the mechanism of the latent heat is not clear during the solidification of metallic glass, it is necessary to study the solidification law of metallic glass.In this paper, water quenching and copper mold casting are used to prepare ZrS / 41T / T / NiSZ / NiSZ / 10 / 10 / CuSZ / Cu / T bulk metallic glass. The temperature field data are collected by means of EM9104C multichannel data acquisition instrument for the solidification process of the bulk metal glass (12.5B / 22.5). The results are as follows: (1) in this paper, the solidification process is studied by means of EM9104C multichannel data acquisition.On the basis of the obtained temperature data, the interfacial heat transfer coefficient between alloy and different heat transfer media is derived and calculated, and the expression of the liquid solid interface advancing velocity in different coordinate systems is given.At the same time, the cooling solidification process of Zr _ S _ I _ (41) Titig _ (14) Nii _ (10) CuT _ (12. 5) Bei _ (22. 5) bulk metal glass was simulated by using the ProCAST numerical simulation software, and the maximum theoretical preparation diameter was predicted.The results of calculation and simulation show that the preparation of metal glass with a diameter of 16mm by water quenching method is 41 / 1 tititiun / Nitix / 10 / 10 / CuSZ / 12.5 / Bei / 22.5) bulk metallic glass.It takes 26.5s for the surface temperature of the alloy to be cooled from 920 鈩，

本文編號：1727103