Al含量对Zr基块体非晶合金力学性能的影响

Mechanical Properties of Zr-Based Bulk Metallic Glasses with Different Al Contents

用铜模吸铸法制备了(Zr64.8/90Cu14.85/90Ni10.35/90)90+xAl10-x(x=-4,-3,-2,0,2,4,6)块体合金,利用X射线衍射仪(XRD)、万能试验机、显微硬度计和扫描电镜(SEM)研究了Al含量对Zr基块体非晶合金力学性能的影响。结果表明:随着Al含量的减小,合金先是从非晶相为主的非晶/晶体复合材料转变为完全非晶材料,接着转变为以晶体相为主的非晶/晶体复合材料,最后转变为完全晶体材料。表明通过调整Al的含量,可以制备出具有完全非晶结构的Zr基块体非晶合金。当x=-2时,即合金成分为Zr63.36Cu14.52Ni10.12Al12时,合金为完全非晶结构,该合金的室温压缩塑性应变达到20.6%,应力-应变曲线体现出了'加工硬化'特性,屈服强度σs、极限强度σm和断裂强度σf分别为1740.6,2030.7和1510.5 MPa。表明通过调整Al的含量,可以制备出具有优良室温压缩塑性的Zr基块体非晶合金。随着Al含量的减小,合金试样的显微硬度的总体趋势为先增大再减小。当x=2时,合金为非晶/晶体复合材料,该合金具有较高的显微硬度HV719.8。

（Zr64 8/90 Cu14,85/90 Ni10.35/90 ）90 ＋ Al10-x bulk alloys with x =-4, -3, -2, 0, 2, 4 and 6 Were prepared with copper mold casting method. The effects of A1 contents on mechanical properties of Zr-based bulk metallic glasses were studied by X-ray diffraction （XRD） , universal testing machine, mierohardness tester and scanning electron microscope （SEM）. The results showed that with the decrease of the content of A1, the structure of alloys changed from amorphous/crystal composite materials with mainly amorphous phase into completely amorphous materials, and then into amorphous/crystal materials with mainly crystalline phase, and finally into fully crystalline materials. It meant that Zr-based bulk metallic glasses with completely amorphous structure could be fabricated by adjusting A1 content. ＂The structure of the alloy was completely amorphous when x = -2, with alloy composition of Zr63,36Cu14.52 Ni0.12A112 , and the compressive plastic strain （ εp ） of the alloy was up to 20.6%. The yield strength （δr ）, maximum strength （ δm ） and faeture strength （δf） were 1740.6, 2030.7 and 1510.5 M Pa, respectively, and the ＂work-hardening＂ characteristic could be seen from the stress-strain curve. It demonstrated that Zr-based bulk metallic glasses with excellent compressive plasticity and high compressive strength could be fabricated by adjusting A1 content. With the decrease of the A1 content, the microhardness of alloy samples firstly in- creased and then decreased. When x = 2, the structure of the alloy was amorphous/crystal composite material, and the hardness reached HV719.8, which indicated that higher mierohardness was obtained in the alloy.