DSpace JSPUI

Age Hardenable Al-Alloys Are Widely Used As Structural Components In Aerospace Applications. It Is Predicted That The Strength Of These Crystalline Alloys (550-600mpa) Could Be Enhanced By 2-3 Times In Amorphous Or Nanocrystal Dispersed Amorphous Condition. In The Past Amorphization In Al-Alloys Was Possible Only By Rapid Solidification Of Multi-Component Complex Melts. In The Present Work, An Attempt Has Been Made To Synthesize Al65Cu20Ti15 And Al50Ti40Si10 Alloys With In-Situ Nanometric Intermetallic Precipitates (Al2Cu, Al5CuTi2, Al4Cu9, Al3Ti Ti5Si3, Al2Ti) And/Or Nano-Oxide (Tio2) Dispersion By Solid-State Mechanical Alloying Route And Consolidate Milled Powder By Different Sintering Methods (Conventional, Spark Plasma, High Pressure, Hot Isostatic Pressing, Etc). Following This Mechano-Chemical Synthesis And Consolidation, Extensive Effort Has Been Undertaken To Characterize The Microstructural Evolution By X-Ray Diffraction, Scanning And Transmission Electron Microscopy, Energy Disperse Spectroscopy, Differential Scanning Calorimetry And Asses Mechanical Properties Including Hardness, Compressive Strength, Elastic Modulus, Wear Resistance And Fracture Toughness. The Present Al Alloys Record Extraordinary Levels Of Compressive Strength (1500-1950 Mpa), Young’s Modulus (130-160 Gpa), Fracture Toughness (3.4±0.8 Mpa√M) And Hardness (7.5-8.8 Gpa) And Measure Up To 2-3 Times Greater Strength Than Age Hardenable (Crystalline) Al-Alloys (< 600 Mpa) And Compare Well With Maraging Steel In Strength But At A Much Lower Density (~ 3.5 Mg/M3). The Novelty Of These Alloys Lies In The Unique Microstructure And Phase Aggregate That Evolve Through Precipitation Of Nano-Metric Intermetallic Phases (Al3Ti, Al4Cu9, Al2Cu And Al5CuTi2.Ti5Si3, Etc.) In Amorphous Matrix By Annealing After Mechanical Alloying (MA) Under Ambient Condition Using High Energy Planetary Ball Milling, Or By Partial Amorphization During Mechanical Alloying Itself. Thus, The Above Results Suggest That Mechanical Alloying Followed By Spark Plasma Or High Pressure Sintering Is A Flexible, Convenient And Promising Route For Synthesizing Ternary Al-Alloys With Nano-Intermetallic/Oxide Dispersed Amorphous Matrix Composite Offering Attractive Mechanical Properties.