Titanium
Multiaxial Stress Critical Plane Fatigue Method
Introduction Uniaxial fatigue methods, whether stress-life, strain-life, or spectral, presume that a single stress or strain component tells the whole damage story. Real hardware disagrees. Shafts carry bending plus torsion, pressure vessel nozzles see biaxial membrane stress plus thermal bending, and vibrating structures respond in… Read more
Why Union Pacific Is Painting Its Rails White: Thermal Stress, Sun Kink, and Coating Chemistry
Union Pacific has begun spraying white paint on the sides of its rails in the hottest sections of its 32,000-mile network. The program, which entered targeted deployment in 2025, uses a hi-rail truck with a spray rig to coat both faces of the rail web… Read more
Stainless Steel Straw Residual Stress
By Tom Irvine While enjoying a glass of orange juice at an outdoor café in Madeira, Portugal on a sunny Independence Day morning, I noticed the reusable stainless steel straw resting across the glass — its elegant curved bend a perfect reminder that one of… Read more
Carbon Steel Marine Corrosion
Photograph taken at a seaside retaining wall in Madeira, Portugal, July 2026. The bolt and nut shown are carbon steel — heavily corroded after prolonged exposure to the Atlantic marine environment.Figure 1. Severely corroded carbon steel bolt and nut at a seaside retaining wall, Madeira,… Read more
Ultrasonic Fatigue Tests
Image Courtesy of http://www.mbrosia.co.kr/en/product/product0101.php Ultrasonic fatigue testing at 20 kHz has become the standard method for characterizing material fatigue in the Very High Cycle Fatigue (VHCF) regime — beyond 107 cycles, extending to 109 (gigacycle) and beyond. At 20 kHz, a test that would require… Read more
A6061-RAM2 Additive Manufacturing Material
A6061-RAM2 is a new aluminum alloy developed specifically for additive manufacturing (AM) that achieves mechanical properties comparable to wrought 6061-T6 — a capability that has eluded conventional AM processes for decades. Developed by Elementum 3D using Reactive Additive Manufacturing (RAM) technology and matured by NASA… Read more
Stress Corrosion Cracking
intergranular SCC of an Inconel heat exchanger tube with the crack following the grain boundaries. photo courtesy Stress corrosion cracking (SCC) is a time-dependent fracture mechanism driven by the simultaneous presence of sustained tensile stress and a corrosive environment. Neither factor alone is sufficient. Their combination… Read more
Fatigue Loads on Fighter Jet Ejection Seat Metal Components
Image courtesy of: https://martin-baker.com/ejection-seats/
The Effect of Inclusions on Metal Fatigue & Fracture
Image courtesy of: https://incastt.com/inclusion-defects-in-investment-casting/ Non-metallic inclusions are unavoidable by-products of steelmaking, casting, and welding. They range in size from sub-micron oxide clusters to hundred-micron sulfide stringers, but their fatigue consequence is disproportionate to their size. This post catalogs the common inclusion species by alloy family,… Read more