This seminar focuses on the characteristics and properties of engineering alloys, and their practical applications in aerospace and other industries where they are utilized. It will enhance attendees' professional skills in design, manufacturing and repair technologies. The relationships between alloy processing, microstructure and properties will be explained and discussed. Microstructures evolving from various heat treatment schedules, and a variety of processes ranging from casting, forging, extrusion, hot isostatic press to powder metallurgy will be compared to illustrate their effects on mechanical properties.

Aluminum alloys, from 2024 to 7075 are widely used in low temperature lightweight structures, and reciprocal engine parts. This seminar will discuss their product forms, strengthening mechanisms, environmental durability, and mechanical properties. Titanium alloys are used for various aircraft parts and other structural components because of their lightweight and strength. The microstructure of a titanium alloy varies dramatically when subject to different heat treatment schedules, and so do the subsequent mechanical properties. These changes will be discussed along with examples of real-life applications. Ferrous alloys including stainless steel and cast iron are used for their respective unique characteristics. Properties and applications of these alloys will be discussed. Ni-base alloys, for example Inconel 718, are often referred to as superalloys due to their durability of strength at elevated temperatures. Alloy strengths at high and low temperatures are attributable to different strengthening mechanisms. These factors directly affect part and structure failure modes and fractography; transgranular at low temperature, and intergranular at high temperature.

The suitability of individual engineering alloys for specific applications are contingent on the controlling critical factors in each case. Fracture toughness and tensile properties are the determining factors if an engineering alloy is used for static structure at room temperature. Low cycle fatigue resistance is the critical factor to determine if an engineering alloy is suitable for a rotating part. Creep and stress rupture characteristics are the properties to be checked before any alloys can be safely used for high temperature applications. This course will provide attendees with knowledge to evaluate available engineering alloys, judging from their critical properties, for specific applications.

Attendees are encouraged to bring in their own real-life cases.

• Recognize the effects of materials processing on microstructure and properties
• Formulate proper heat treatment schedules of A1, Ti, ferrous alloys and Ni-base superalloys for their respective applications
• Judge the suitability of an engineering alloy for a specific part or structure
• Demonstrate a high professional knowledge in general applications of engineering alloys
  

• Alloy Structure and Product Form
  • Structure of engineering alloys
  • Miller Indices, slip systems and defects
  • Effects of process and product form on mechanical properties
• Alloy Phase Formation and Identification
  • Phase diagram
  • Isothermal transformation and continuing cooling curves
  • Microstructure evolution
• Tensile Properties and Hardness Measurement
  • Tensile test and stress-strain curve
  • Theoretical shear strength
  • Hardness measurement
• Fracture Toughness
  • Fracture toughness in design and failure analysis
  • Ductile to brittle transition
• Low-cycle and High-cycle Fatigue Life Prediction
  • Low cycle fatigue life prediction
  • High cycle life calculation
  • Goodman diagram
  • Thermal mechanical fatigue
• Creep and Stress Rupture
  • Materials behavior at elevated temperature
  • Creep test and mechanisms
• Exercise: Fatigue and Creep Life Calculations
  

• Processing of Al Alloys
  • Casting, forging and extrusion, powder metallurgy process
• Al-Cu Alloys
  • Strengthening mechanisms, properties and practical applications
• High-strength Al Alloys
  • Engineering applications of Al-Mg-Zn alloys, and Al-Li alloys
• Oxidation and Corrosion
  • Environmental degradation
• Exercise: Al Alloy Selection in Engine Cylinder Design
  

• Processing of Ferrous Alloys
  • Production of steels
  • Heat treatment and microstructure
  • Hardenability
• Carbon, Alloy and Stainless Steels
  • Alloy designation
  • Mechanical properties of steels
  • Corrosion protection
• Industrial Applications
  • Engine components, landing gear
• Exercise: Establishing Heat Treatment Schedules for Steels
  

• Heat Treatment and Microstructure
  • Phase diagram and heat treatment
  • Microstructure and mechanical properties
• Effects of Processing
  • Triple melting, hard alpha effects
• Mechanical Properties and Environmental Effects
  • Mechanical strength and physical characteristics
  • Flammability
• Engineering Applications of Ti Alloys
  • Engine compressor disks and blades
  • Dwell time creep
• Exercise: Dwell Time Fatigue Analysis
  

• High Temperature Alloy Characteristics
  • Creep and stress rupture
  • Transgranular and intergranular fracture mechanisms
• Characteristics of Ni-base Superalloys
  • Cast, forged, powder metallurgy, and single crystal
• Applications at Elevated Temperatures
  • High temperature turbine disks
  • Stress concentration
  • Coating
• Exercise: Design Project with Ni-base Superalloys
  

• Alloy Selection in Engineering Design
  • Strength and safety requirements
  • Fatigue, fracture toughness and damage tolerance
  • Environmental awareness
  • Effects of operating conditions
• Critical Alloy Characteristics in Manufacturing
  • Ductility and superplasticity, machinability, and formability
• Alloy References
  • Alloy codes, classifications and specifications
  • Engineering alloy references
  • International alloy cross references
• Engineering Alloys and Repairing
  • Weldability, post repair heat treatment
• Case study
  • Alloy selection for engine turbine blades
  • Alloys for airframe structure
  • Candidate alloys for a rotating shaft