Preparation And Properties Of 2D-MXene Reinforced Copper Matrix Composites

This study works on high strength and toughness MXene reinforced copper matrix composites,focus on the design,preparation and structure control of MXene,the wettability of MXene and Copper Matrix,and the structure and properties of MXene reinforced copper composites.Two-dimensional?2D?MXene with different composition and structure were prepared by optimizing etching parameters;The MXene stacked structure was further dispersed by pretreatment of MXene powder,and the MXene with two-dimensional lamellar structure was obtained;The surface-modified MXene powders were prepared by chemical intercalation and annealing process to control the structure of the surface.On this basis,the MXene/Cu powers were prepared by high energy ball milling,and the MXene/Cu composite was prepared by Powder metallurgy method.The influence of preparation process and microstructure on the properties of MXene/Cu composites was revealed by studying the phase,microstructure and mechanical properties.The main results are as follows:?1?2D-MXene with different composition and structure was prepared with optimizing etching parameters by using HF aqueous solution as etching agent and Ti₃AlC₂ as initial powder.Gallery Al atoms in Ti₃AlC₂ were partly removed by 10wt.%HF aqueous solution etching 1.5 h to obtain MXene keeping appropriate Al interlayers,Al atoms in Ti₃AlC₂ were fully removed by 20 wt.%and 40 wt.%HF aqueous solution etching 5 h;By means of homogenization,the MXene lamellae were further opened,and the"accordion"structure is transformed into a two-dimensional sheet structur.?2?The surface structure of MXene was controlled by a combination of chemical intercalation and annealing;The contents of functional groups-O,-F and-OH on the surface of MXene were reduced by annealing at 750°C;Ni nanoparticles were successfully formed on the surface of MXene by Ni ion intercalation and annealing reduction process,and the Ni nanoparticles modified MXene was obtained.?3?The wettability of two kinds of MXene and copper at high temperature was studied,it was found that the surface functional groups of annealed MXene were reduced to some extent,but the high temperature wettability of MXene with copper was still poor;Ni nanoparticles modified MXene and copper have good wettability at high temperature,this is mainly through the high temperature alloying of Cu and Ni to achieve the mutual diffusion of Cu and Ni atoms so as to improve the wettability.?4?The MXene-cu composite powders were prepared by high energy ball milling from annealed Mxene,Ni nanoparticles modified MXene and Al partly removal MXene;The MXene/Cu composites were prepared by hot-pressing sintering.The microstructure of MXene-Cu composite powder was observed,it was found that MXene dispersed uniformly in the matrix to form sub-micron MXene dispersion particles with the increase of milling time.The size and distribution of MXene in the prepared MXene/Cu composites are basically the same as those in the composite particles.?5?The tensile strength of mxene/Cu composite was 286 MPa and the elongation was 5.6%,the MXene composite was prepared by modifying Ni nanoparticles,at the same volume content,the tensile strength reached 327 MPa and increased 14.3%,the elongation increased 156%,this is mainly due to the improvement of the wettability of MXene and matrix,and the further improvement of the interfacial bonding properties between MXene and matrix.The MXene/Cu composite with Al partly removal is helpful for improving the ductility of the material.However,because of the larger particles in the reinforced phase,the number of the whole reinforced phase decreases,the strengthening effect decreases,and the mechanical properties of the material also decreases.