Densification mechanism of Ti-Al-Nb alloys pressurelessly sintered from Al-Nb master alloy powder for cost-effective manufacturing

In situ investigation on densification mechanism of Ti-20Al-19Nb (at.%) alloy by TiH2-assisted pressureless sintering

“…2(e-h) shows the SEM image of the mixed powder and corresponding element mappings for the Ti, TiH 2 , Al, and Nb powders. Those for the Ti, Al, and Nb powders have been shown in our previous studies [21]. The Al particles remained in their original morphology, and they adhered to the Ti and Nb particles.…”

“…For a Ti 44 Al 48 Nb 8 alloy with low Nb content, the large-scale components with desired shapes were prepared by the electromagnetic levitation method and pressure die-casting [5,6]. However, the Ti- (18)(19)(20)(21)(22)(23)(24)(25)(26)(27)(28)(29)(30)Al- (12.5-30)Nb (at.%) alloys with high Nb content may contain intermetallic phases of Ti 3 Al (α 2 ) and Ti 2 AlNb (O) with a high alloying degree, and element segregation will occur during smelting. As far as the deformation processing, harsh conditions are required for Ti-22Al-25Nb alloys with intrinsic brittleness [7].…”

“…For Ti- (18)(19)(20)(21)(22)(23)(24)(25)(26)(27)(28)(29)(30)Al- (12.5-30)Nb (at.%) alloys, the raw materials were normally the costly pre-alloyed powders when the SPS and HIP methods were used. With the continuous progress in powder metallurgy, researchers intended to fabricate high-density structural materials with a low production cost [17].…”

“…However, high porosity was the main drawback for the pressureless-sintered Ti-12Al-41.2Nb (wt.%) alloys [18] and powder metallurgic Ti-49Al (at.%) alloys [19,20], which might result in inferior mechanical properties. Recently, a dense Ti-22Al-17.5Nb (at.%) alloy was fabricated from Al-Nb master alloy powders by pressureless sintering, and its tensile strength was improved at room temperature and 600 °C compared with that of the alloy prepared from pure Al powder [21]. With the intense development of the Ti-Al-Nb alloy, the refractory Ta, Mo, and Hf elements were incorporated to regulate the proportion and morphology of the intermetallic phases [22].…”

Facile Fabrication of High‐White and Robust Superhydrophobic Ni/Al2O3 Composite Coating on Al Alloy

“…As a metallic material with high specific strength, lightweight, and good corrosion resistance, Al alloy has become one of the primary metal materials used in aircraft, automobiles, buildings, and ship manufacturing industries, which has outstanding application performance and promising application potential. [17][18][19][20] However, the massive-scale utilization of Al and its alloys is constrained by the influential factors from the environment owing to its susceptibility to corrosion in acidic, alkaline conditions, salt solution, and oxygenated circumstances. [21][22][23] During the past decades, superhydrophobic films based on Al alloy have been gradually developed and widely used.…”