Showing 117 results for Author: James A. Haynes
Sep, 2026
Journal
The use of recycled or scrap or secondary aluminum to manufacture high pressure die castings (HPDC) for structural applications is an opportunity to reduce cost, energy expenditure and emission of greenhouse gases. Technical challenges that must be overcome to achieve this on a large scale include scrap sorting and availability of alloys that can take such feedstock while…
Sep, 2026
Conference Paper
Aug, 2026
Conference Paper
Oak Ridge National Laboratory (ORNL) has recently launched an effort to economically expand the North American aluminum supply chain by designing and developing a new family of Al-Mg-Si-Fe-Mn structural die cast aluminum alloys that can be made from up to 100% mixed 5xxx and 6xxx series automotive post-consumer sheet scrap and do not require heat treatment. The goal is to…
Aug, 2026
Conference Paper
Jul, 2026
Journal
Binder Jet Additive Manufacturing (BJAM) is a promising manufacturing pathway to produce H13 steel dies and tooling with complex geometries for applications in high pressure aluminum die casting, hot stamping, and injection molding. While fully dense H13 coupons produced using BJAM have been subjected to detailed microstructure characterization, properties which are critic…
May, 2026
Journal
As-solidified microstructures of near-eutectic alloys often contain multiple primary phases that are not expected from equilibrium phase diagrams. Such microstructures are caused by cooling-rate-dependent solidification pathways, a factor not captured by the Scheil–Gulliver model or variations thereof. Here, we present a model and algorithm that incorporate the critical nu…
Mar, 2026
Conference Paper
High temperature ferritic-martensitic steels are candidate materials for heavy-duty diesel engine pistons. The envisioned transition to hydrogen blended fuels is expected to alter the post-combustion atmosphere in the engines, primarily resulting in a higher water vapor content (> 20 vol%) and potentially higher exhaust gas temperatures. The oxidation resistance of existin…
Mar, 2026
Conference Paper
There is a growing trend to die cast structural automotive components from scrap aluminum sources to reduce embodied energy and cost. However, the ability to include most post-consumer scrap is severely limited due to the sensitivities of current industrial high pressure die cast (HPDC) Al alloys to Fe impurities introduced during the recycling process. This study characte…
Dec, 2025
Journal
A new, solute-lean Al-0.3Zr-0.2Ce-0.2Cu (wt.%) alloy is developed for additive manufacturing that overcomes the classical tradeoff between conductivity and creep resistance. The rapid-cooling-enabled supersaturation of Zr, and its uniform distribution in α-Al matrix, along with formation of submicron (Ce,Cu)-rich intermetallic particles on solidification lead to unusually…
Dec, 2025
Journal
The study investigated how post‐weld heat treatment (PWHT) temperature affects the microstructure and localized deformation/fracture during bend testing of rotary inertia friction welds (RIFW) between AISI 422 stainless steel and AISI 4140 steel. RIFW produced a fully martensitic interface with approximately 550 HV hardness in both the thermo-mechanically affected (TMAZ) a…
Dec, 2025
Journal
Heat-resistant steels with high chromium additions (≥5 weight percent) are critical for many high temperature energy and manufacturing applications, including heat exchangers, pistons for engines, and dies for metal working and casting. However, while high chromium additions increase oxidation resistance at elevated temperatures, they also compromise thermal conductivity,…