冷-热处理对Zr基块体非晶合金结构和性能的影响

Effect of cold-heat treatment on structure and properties of Zr-based bulk amorphous alloys

摘要:

传统晶态材料构件或装备在低温环境中会出现可动部分卡死、龟裂、特性改变甚至脆性断裂等现象。低温极端条件如温度突变、高应变速率冲击等对材料性能带来的不利影响严重制约了其在低温极端环境领域的应用。块体非晶合金在低温条件下具有强度更高塑性更好的特殊性能,在极地科考以及航空航天等极端条件下具有极大的应用优势。本文以(Zr_0.6336Cu_0.1452Ni_0.1012Al_0.12)₉₇Tm₃块体非晶合金为研究对象,研究冷-热处理时间对块体非晶合金的结构、力学性能和腐蚀性能的影响。结果表明,当处理时间由30 min延长到90 min时,试样的晶化体积分数从2.3%增加到4.0%,屈服强度由1701 MPa增加到1810 MPa。在3.5 wt.% NaCl溶液中,合金具有较小的自腐蚀电流密度与较大的电化学阻抗,这意味着经冷-热处理后的块体非晶合金具有优异的耐腐蚀性能。本研究为块体非晶合金在低温极端环境领域的应用提供了强有力的理论支撑。

Abstract:

In the cryogenic temperature environment, the movable parts of traditional crystalline components or equipment will be stuck, cracked, characteristic change and even brittle fracture. The influence of cryogenic extreme environment such as temperature mutation and high strain rate shocks on metallic glass severely restricts its application in industry. Due to special properties of higher strength and better plasticity at cryogenic temperature, bulk metallic glass has great application advantages in extreme conditions such as polar scientific research and aerospace. A (Zr_0.6336Cu_0.1452Ni_0.1012Al_0.12)₉₇Tm₃ bulk metallic glass was chosen in this paper, and the effect of cold-heat treatment time on the microstructure, mechanical properties and electrochemical corrosion resistance were studied. It is found that when the treatment time is set from 30 min to 90 min, the crystallization volume fraction of specimens increases from 2.3% to 4.0%, and the yield strength increases from 1701 MPa to 1810 MPa. The smaller self-corrosion current density and larger electrochemical impedance in 3.5 wt.% NaCl solution indicate that the bulk metallic glass has excellent corrosion resistance after cold-heat treatment. This study provides a strong theory support for the application of bulk metallic glasses in cryogenic temperature extreme environment fields.