Study On Microstructure And Properties Of Low-pressure Cold Spray Copper-based Materials

According to the current research situation of low-pressure cold spraying copper-based materials,this paper adopts low-pressure cold spraying technology to prepare copper-based materials and perform subsequent modification treatment.Scanning electron microscopy?SEM?,transmission electron microscopy?TEM?,energy spectrometer?EDS?,and X-ray diffraction?XRD?were used to study and analyze the micro-morphology,element distribution,and phase of copper-based materials.Through hardness and tensile experiments,friction experiments and corrosion experiments to study the comprehensive performance of copper-based materials,the main conclusions are:The copper-based bulk materials were prepared by low-pressure cold spray additive manufacturing technology.The thermal conductivity and mechanical properties of the bulk materials were tested.The results show that the thermal conductivity of copper-based bulk materials prepared from copper-based powders with a volume ratio of 10%Al₂O₃ is better.With the increase of Al₂O₃ content,the thermal conductivity decreases.After annealing,the cold-sprayed copper-based bulk material has improved thermal conductivity and mechanical properties.The thermal diffusivity and tensile strength show a trend of increasing first and then decreasing with the increase of annealing temperature.When the annealing temperature is 500?,the thermal diffusivity of the heat-treated copper-based bulk material is 80.43%of the processed copper bulk material,the tensile strength is 125.3 MPa.By modifying the cold sprayed copper-based material coating by induction remelting technology,the high aluminum bronze alloy coating was successfully prepared.The high-aluminum bronze alloy coating is denser than the cold spray coating,and the coating has good alloying effect,and the performance is significantly increased.The obtained alloy coating forms?phase,?phase,?2 phase,and?phase,and has the same phase composition as that of the as-cast high-alumina bronze bulk alloy.The in-situ synthesized high-aluminum bronze alloy coating has good mechanical properties and wear resistance,and the performance is close to that of the as-cast bulk alloy.The hardness of the prepared alloy coating is 357.0 HV,and the friction coefficient of the high-aluminum bronze coating/Al₂O₃ friction pair is 0.320under dry friction conditions.In-situ synthesis of high-aluminum bronze alloy coatings in induction remelting shows corrosion resistance similar to that of as-cast bulk alloys in 3.5wt.%NaCl and 5.0wt.%H₂SO₄ corrosion media.AlCoCrCuFe high-entropy alloy coatings were synthesized in situ by cold spraying?CS?and induction remelting.The morphologies of the as-synthesized coatings are simple and mainly composed of body-centered cubic?BCC?and face-centered cubic?FCC?phases.The BCC phase possess an amplitude-modulated structure consisting of the B1-disordered phase?FeCr?and the B2-ordered phase?AlCo?,and the nano-scale BCC phase structure precipitate near the grain boundary.The FCC phase is composed of a solid solution structure of the Al-Cu base and manifested the characteristics of a typical twin structure.The average micro-hardness of the as-synthesized AlCoCrCuFe high-entropy alloy coatings is found as 528.2HV.Under dry-friction conditions,the friction coefficient and wear rate of the AlCoCrCuFe coating/Al₂O₃ friction pair are 0.379 and 0.703×10^-55 mm³/?N?m?,respectively.