Thermodynamics Description Of Ti-Cu-Ni-B System And The Study Of Its Glass-forming Ability

Titanium alloy has the characteristics of high specific strength,resistance to oxidation at room temperature,corrosion resistance and high temperature resistance.It is widely used in many fields such as biomedicine,aerospace,marine vessels,military weapons,metal anticorrosion,and has very good application prospects.The titanium-based bulk glass alloy has more excellent characteristics and has been widely studied and paid attention to.At present,titanium-based glass alloys whose critical dimensions are greater than 5mm contain high-cost or highly toxic elements such as Pd or Be.Therefore,the development of non-toxic and inexpensive titanium-based glass alloys has great practical significance..In this paper,among all the bulk titanium-based glass alloys currently developed,the Ti-Cu-Ni system,which is low in cost,safe and non-toxic,and has better glass forming ability is selected.The method of calculation of phase diagrams（CALPHAD）is used to guide the addition of non-metallic element B to the Ti-Cu-Ni system to improve the glass forming ability of the system.Mainly carried out the following work:（1）The isothermal section of Ti-Cu-B ternary system is studied at 1073K by electron probe（EPMA）,X-ray diffraction（XRD）and other test methods using equilibrium alloy method.The B-Cu binary system was re-optimized using the CALPHAD method,and the thermodynamic description of the B-Cu-Ti ternary system was established.（2）According to the Cu-Ni-Ti ternary thermodynamic parameters reported in the literature,the thermodynamic parameters of B-Cu-Ti and B-Cu-Ni worked in this paper and the thermodynamic parameters of B-Ni-Ti modified in the literature,the extrapolation establishes Ti-Cu-Ni-B quaternary The thermodynamic database,and the quaternary zero-variable reaction is calculated.（3）The experimental composition is designed by doping and replacing the B element in the Ti-Cu-Ni ternary system,and the glass forming ability of the system is studied by the copper mold suction casting and the melt-spinning ribbons.The deep eutectic reaction of Ti-Ni-B system and Ti-Cu-Ni-B system was calculated by thermodynamic database,and Ti-Ni-B and Ti-Cu-Ni-B experiments were designed.At a spin rate of 20m/s,glass ribbons Ti₆₀Ni_33.6B_7.4 and Ti_38.2Ni_52.5B_9.3 were prepared successfully.At the same rate,Ti_54.2Cu_31.2Ni_9.4B_5.2 almost completely glass ribbons were prepared.To obtain a quaternary amorphous with higher amorphous forming ability,further research is needed at the composition near the eutectic point.