Numerous strengthening methods have been proposed and developed to restore the fatigue performance of metal components using the CS process. However, this remains a significant challenge. Thus, it is an urgent need to rationally design the CS process to achieve high-performance repair of damaged components. Cracks in components are common defects in engineering. This cannot satisfy the demand for application as bearing parts or operation in a vibration cyclic loading environment. After CS repair, the fatigue limit was restored to 117 ± 30 MPa, which is approximately 77.0% of the original value. For example, in our work, the fatigue limit of the original 7075 Al alloy specimens was 152 ± 7 MPa, whereas that of samples with pre-cracks decreased sharply to 54 ± 2 MPa. However, a significant challenge for the CS technology is that the fatigue performance of damaged components repaired by CS generally cannot be compared with that of the original state (Bagherifard and Guagliano, 2020 Sample et al., 2020). Thus, it is a lucrative technique for developing freeform and coatings from temperature-sensitive materials (such as Al, Mg, Cu, and amorphous alloy). The CS process relies only on the kinetic energy of powder particles to achieve material build-up and does not involve high temperature inputs. This study demonstrates that this compound process of CS technology and laser processing presents a wide range of possibilities for further development of advanced repair technology.Ĭold spray (CS) is an attractive additive manufacturing technology that utilises high-velocity microparticles to impact the substrate and produce a deposition. Through the combination of these two lasers, the fatigue performance of CS-repaired Al alloy samples is successfully restored to its original condition. Next, another nanosecond laser is used as a post-treatment to act on the area except the repaired region of the sample, which optimised the residual stress distribution around the repaired zone by the mechanical effects of the laser-induced ultra-high shock waves. Thus, the bonding strength is significantly improved. ![]() In the treatment, a millisecond laser is used during the CS process to heat the impact location in situ, by which the bonding mode is transformed from mechanical bonding to metallurgical bonding, and massive Al 2O 3 reinforcements of nano/micro size are formed in the coating. This study proposes a novel and promising approach to recover the fatigue performance of CS-repaired Al alloy components using two laser beam modulations. ![]() However, owing to the lower bonding strength and inhomogeneous residual stress field distribution, the fatigue performance of CS deposition cannot satisfy the requirements of numerous engineering conditions. There's also the fact that random inputs are actually "even" every 12 inputs will include 6 Phosphorus and 6 Silicon atoms, though you certainly don't need to know that to complete this puzzle or any random puzzles.The cold spray (CS) process has been demonstrated to be an attractive additive manufacturing technology for the development of freeforms and coatings from temperature-sensitive materials. If you get a Phosphorus atom again, then this time you can use that spare molecule and only bring through 1 Hydrogen molecule.Īlternatively, what if you ignored the fact that the inputs are uneven? It's awkward that you have 2 Hydrogen atoms in each input. In state 1, if you get a Silicon atom, then you don't need to use up that spare atom. This moves you to state 1, because you've got 1 spare. ![]() If you get a Phosphorus atom, then bring through 2 Hydrogen molecules and bond them to make Phosphine and a spare Hydrogen atom. ![]() If you get a Silicon atom, then bring through 2 Hydrogen molecules and bond them to make Silane. Initially, you have no hydrogen atoms stored. It could lead to a stockpile if you're not careful, yes! So, keeping that in mind, what you need to do, is make sure that you use up that stockpile.
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