Chalk River Laboratories

About: Chalk River Laboratories is a based out in . It is known for research contribution in the topics: Neutron diffraction & Neutron scattering. The organization has 2297 authors who have published 2700 publications receiving 73287 citations.

Studies in tetrapartite symbioses

Abstract: Alnus incana seedlings were successfully inoculated with an endomycorrhizal fungus (Glomus fasciculatus), an ectomycorrhizal fungus (Paxillus involutus) and an isolate ofFrankia (ACN1) simultaneously. The effects of the inoculation treatments on the growth performance of the seedlings were evaluated under controlled conditions.

Experimental study of residual stresses in laser clad AISI P20 tool steel on pre-hardened wrought P20 substrate

Abstract: Laser cladding is to deposit desired material onto the surface of a base material (or substrate) with a relatively low heat input to form a metallurgically sound and dense clad. This process has been successfully applied for repairing damaged high-value tooling to reduce their through-life cost. However, laser cladding, which needs to melt a small amount of a substrate along with cladding material, inevitably introduces residual stresses in both clad and substrate. The tensile residual stresses in the clad could adversely affect mechanical performance of the substrate being deposited. This paper presents an experimental study on process-induced residual stresses in laser clad AISI P20 tool steel onto pre-hardened wrought P20 base material and the correlation with microstructures using hole-drilling and neutron diffraction methods. Combined with X-ray diffraction and scanning electron microscopic analyses, the roles of solid-state phase transformations in the clad and heat-affected zone (HAZ) of the substrate during cladding and post-cladding heat treatments on the development and controllability of residual stresses in the P20 clad have been investigated, and the results could be beneficial to more effective repair of damaged plastic injection molds made by P20 tool steel.

Effect of uniaxial strain on the structural and magnetic phase transitions in BaFe2As2.

Abstract: We report neutron scattering experiments probing the influence of uniaxial strain on both the magnetic and structural order parameters in the parent iron pnictide compound, ${\mathrm{BaFe}}_{2}{\mathrm{As}}_{2}$. Our data show that modest strain fields along the in-plane orthorhombic $b$ axis can affect significant changes in phase behavior simultaneous to the removal of structural twinning effects. As a result, we demonstrate in ${\mathrm{BaFe}}_{2}{\mathrm{As}}_{2}$ samples detwinned via uniaxial strain that the in-plane ${C}_{4}$ symmetry is broken by both the structural lattice distortion and long-range spin ordering at temperatures far above the nominal (strain-free) phase transition temperatures. Surprising changes in the magnetic order parameter of this system under relatively small strain fields also suggest the inherent presence of magnetic domains fluctuating above the strain-free ordering temperature in this material.