Effect of carbon addition on microstructure and mechanical properties of Ti-based bulk metallic glass forming alloys

A kind of novel Ti-based composites was developed by introducing different amounts of carbon element to the Ti50 Cu23 Ni20 Sn7 bulk metallic glass forming alloys. The thermal stability and microstructural evolution of the composites were investigated. Room temperature compression tests reveal that the composite samples with 1% and 3% （mass fraction） carbon additions have higher fracture strength and obvious plastic strain of 2 195 MPa, 3. 1% and 1 913 MPa, 1.3% respectively, compared with those of the corresponding carbon-free Ti50 Ni20 Cu23 Sn7 alloys. The deformation mechanisms of the composites with improved mechanical properties were also discussed.     

Corrosion of Glassy (Ni8Nb5)99.5Sb0.5 Alloy and Stability of Passive Film

通过浸泡法和电化学腐蚀法研究了(Ni8Nb5)99.5Sb0.5非晶在1,6mol/LHCl,1mol/LH2SO4和3%NaCl(质量分数)溶液中的腐蚀行为,对相应的组分金属Ni,Nb和Sb的腐蚀行为进行了比较。钝化膜的稳定性使用恒电位法和XPS深度剖析进行了研究,电化学极化测试后用扫描电镜观察了合金的表面形貌。结果表明,Ni-Nb-Sb合金在1mol/LHCl,1mol/LH2SO4和3%NaCl(质量分数)溶液中具有良好的抗腐蚀性,在6mol/LHCl溶液中,非晶合金的抗腐蚀性较差。在含有氯的介质中,电化学腐蚀后非晶合金表面被晶化,且有过钝化溶解。对钝化膜的稳定性研究表明,在低电压下,钝化膜的生长是由扩散控制的,而在高电压下,则主要呈活化腐蚀。