Research On SPS Sintering Preparation Technology Of Ti-based Amorphous Alloys

Owing to the excellent mechanical propertier, Ti-based amorphous alloys has been anew kind of promisssing functional materials, but the Ti-based bulk amorphous alloys cannot be prepared by traditional preparation technology, which has highly restrict industryapplication of amorphous alloys. the study emphasize on the preparation ofTi₅₂Al₂₀Ni₂₀Cu₈bulk amorphous alloys by mechanical alloyings technology（MA） andspark plama sinteing technology（SPS）.The height of the sample is7mm,and the diameterof the sample is20mm.Firstly，mechanical alloying technique was used to prepare Ti₅₂Al₂₀Ni₂₀Cu₈amorphousalloy powders,metal powders was used as original materials,which was prepared byTi-Al-Ni-Cu metal element,the revolving speed was300r/min,the material ratio was30:1,the Ti₅₂Al₂₀Ni₂₀Cu₈amorphous alloy powders were prepared in the argonenvironment,and there was no process control agent（PCA） in the MA process.X-raydiffraction（XRD） was used to analyse the variation regularity of metal powder intensitiesduring the milling processs, when the milling time reached35h, the metal powder hadchanged to be amorphous alloys through solid-diffusion reaction; Scanning electronmicroscopic（SEM） was used to observe microscopy and size variation of grainparticles;Differential scanning calorimety （DSC） was used to analyse the thermal stabilityof Ti₅₂Al₂₀Ni₂₀Cu₈amophous alloy powders, calculate the glass transition temperatrue andcrystallization temperature, determine the SPS sinteing temperature region; Kissinger andOzawa equations were used to analyse the Activation energy and freqvency factor incrystallization process of amorphous alloys, in addition, the relationship betweencrystallization volume fraction and temperature was anlaysed.The spark plama sintering technique was used to prepare Ti-based bulk amorphousalloys. the study emphasized on the influence of sintering tempretrue、sintering pressureand holding time on the compressive strength、density and vickers hardness of sinteringbulk sample. The result indicated that the sintering bulk showed the best mechanicalproperties, when the amorphous alloy bulk sample was prepared in the500MPa-570℃-10min sintering conditions. in the subject, when the relative density reached up to97ï¼…, the density had been up to5.21g/cm3, the hardness had been high to900HV, and the highest compressive strength has been1300MPa. The influence ofsintering pressure and holding time on crystallization is weak, when the sinteringtemperature was close to the crystallization tempratrue, the Ti-based bulk amorphousalloys crystallized badly,the Scanning electron microscopic and Energ-dispersivespectroscopy（EDS）was used to analyse the breakage feature, the picture indicate that thethe sample breakage was fragility, and the final sintering composition isTi_52.34Al_20.43Ni_19.54Cu_7.69.