Browse Topic: Peening
Impacts of laser shock peening (LSP) on the evolution characteristics of microstructure in commercially pure α-phase titanium (α-Ti) are explored by molecular dynamics (MD) simulations of high strain-rate compression. The EAM potential (Zhou potential) is selected for its ability to capture the evolution of microstructures. Considering the LSP-induced peak plasma pressure, the strain rate during the simulated shock compression process is set at 10^9 s-1 to replicate the LSP process. The stress-strain curve of the α-Ti under high strain-rate compression is obtained. The maximum equivalent stress reaches 3.6 GPa, consistent with the theoretically calculated value. The simulation results reveal that mechanical twins (MTs) are activated at a strain of 3%. The number of mechanical twins increases and eventually stabilizes, forming a network structure throughout the grains. In the meantime, numerous partial dislocations are generated adjacent to the grain boundaries. The dislocation density also increases with strain and dislocation reactions occur. Moreover, grain refinement is identified. The grain size is refined from the initial ~ 8 nm to ~ 4 nm in the polycrystalline α-Ti. Twinning, together with dislocation-mediated plasticity, drives the refinement of grain size. Gradients of twin density, dislocation density, and grain size density are induced by LSP on the surface of α-Ti. This study comprehensively investigates how LSP influences the evolution of microstructures by MD simulations. It develops an innovative numerical strategy that offers a foundation for elucidating the underlying mechanisms of LSP.
This specification, in conjunction with the general requirements for peening media covered in AMS2431, establishes the requirements for the procurement of ceria-zirconia ceramic shot.
This specification, in conjunction with the general requirements for peening media covered in AMS2431, establishes the requirements for the procurement of yttria-zirconia ceramic shot.
This specification, in conjunction with the general requirements for peening media covered in AMS2431, establishes the requirements for the procurement of conditioned carbon steel cut wire shot with a hardness of 55 to 62 HRC.
This specification, in conjunction with the general requirements for peening media covered in AMS2431, establishes the requirements for the procurement of conditioned carbon steel cut wire shot with a hardness of 45 to 52 HRC.
This specification, in conjunction with the general requirements for peening media covered in AMS2431, establishes the requirements for the procurement of conditioned stainless steel cut wire shot.
Shot peened components present a challenge for the structural analyst when nicks, scratches and gouges are discovered. A common repair scheme calls for blending away of the defect with an appropriate grit abrasive. Though the blending operation removes the defect, it also takes away a portion the beneficial compressive layer as well as the cold-worked material. Large repair facilities may have touch-up shot peen capability but technicians in a field repair setting typically do not. If the shot peen cannot be restored, the structural analyst must have a method to quantify the effect on fatigue life of the repaired part. The purpose of this technical paper is to substantiate analytical techniques for evaluating the fatigue life of a shot peened part after a blend operation. In addition to practical methods to estimate the magnitude of the residual stresses, a numerical method is introduced using finite element modeling of shot peen impacts with non-linear finite element code and validation by a simulated Almen strip.
Improvements in component/system design is a daily challenge these days, always looking for high performance, reduced mass and low costs. The source for the best fit between these factors, coupled with adequate durability performance, is crucial to the success of a given product and this is what motivates engineering teams around the world. The demand for efficient projects with short deadlines for validation and certification is huge and simulation tools focused on accelerated durability and virtual validation are increasingly being used. When developing a new spring for commercial vehicles, lessons learned from the actual loads applied to the suspension are the “key” to a successful project. The loads/stresses from the ground (vertical loads, lateral loads, longitudinal and braking loads) are quite high and, consequently, relevant to the proper definition of the design of the suspension components. The objective of this work is to describe the main development activities faced during a completely new spring development, passing through the design, considering all the limit conditions related to the raw material, lamination process, tempering, rhinestone/shot peening, prefixing and, finally, the load conditions for an adequate fatigue life. The methodology adopted for the definitions of load and fatigue in a bench test is part of this document and, in the end, all iteration results, such as correlation with the application, the MBS and FEA models to be fed again until final validation in a vehicle. This document is a joint development made in partnership between Thyssen Krupp Springs and Stabilizer Bars, Dana Corporation and Volkswagen Truck & Bus (VWTB).
This specification, in conjunction with the general requirements for peening media covered in AMS2431, establishes the requirements for the procurement of cast steel shot with a hardness of 55 to 62 HRC.
This specification, in conjunction with the general requirements for peening media covered in AMS2431, establishes the requirements for the procurement of conditioned cast steel shot with a hardness of 45 to 52 HRC.
This specification covers a low-alloy steel in the form of wire supplied as coils, spools, and straight lengths.
This specification covers the engineering requirements for electrodeposition of cadmium-titanium on metal parts and the properties of the deposit.
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