| Guide device is an important part of the steel rolling production line,which has a great impact on the production efficiency and quality of steel.However,the existing guide material is easy to fracture and poor wear resistance at high temperature,so it is difficult to meet the requirements of high temperature and high speed friction environment.In this topic,rGO/TiCN-W-Cu composites were prepared by plasma sintering(SPS)technology by doping trace Titanium Carbonitride(TiCN)particles and Graphene oxide(GO)powder,and the structure and properties of the composites were studied.It is expected to meet the requirements of wear resistance of guide materials.In this paper,copper-coated tungsten composite powder was prepared by electroless copper plating.SPS technology was used to explore the effects of different sintering processes on the microstructure and properties of the composite materials,and the friction and wear properties of the composite materials were studied under high temperature environment and in corrosive media.The results show that:The copper-coated tungsten composite powder with good surface structure and dense coating structure was successfully prepared by electroless plating.rGO/TiCN-W-Cu composites were prepared by SPS technology at sintering temperature of 1050℃,holding time of 6 min,TiCN of 1.5 wt.%and GO of 0.3 wt.%.The highest density was98.6%and the hardness was 236.53h V.Compared with the w-Cu composite without GO and TiCN powder,the increase was 4.3%and 34.2%,respectively.Appropriate amount of GO can improve the wettability between W and Cu phases,promote the rearrangement of W particles,and generate WC intermediate phase to enhance the interface bonding strength.TiCN particles can pin dislocations and disperse in the matrix for strengthening,thus obtaining dense and uniform structure and improving density and hardness.rGO/TiCN-W-Cu composites have better wear resistance at room temperature and high temperature than W-Cu composites.At 25℃,the wear rate and friction coefficient of rGO/TiCN-W-Cu composites decrease by 64%and 51.9%compared with W-Cu composites,respectively.At 700℃,compared with W-Cu composite material,the decrease is 60%and 58%,respectively.This is because the higher matrix strength of the former can better resist plastic deformation,and under the"pinning"effect of TiCN particles,rGO is easy to form a lubricating film on the wear surface and improve the wear resistance and friction reduction of the material.At high temperature,the hard particles on the surface of the material are connected by the bonding phase Cu to form a hard friction layer,which plays a role of wear resistance and friction reduction.The wear mechanism of rGO/TiCN-W-Cu composites is mainly abrasive wear and fatigue wear.With the increase of temperature,adhesive wear and oxidation wear gradually appear.The friction coefficient of rGO/TiCN-W-Cu composite was the lowest in HCl solution,and the wear mechanism was mainly adhesive wear.The wear rate of rGO/TiCN-W-Cu composite was the lowest in Na Cl solution,and the wear rate was mainly abrasive wear.The composite material has strong passivation ability in HCl solution,and loose passivation layer will be formed after corrosion.However,with the progress of corrosion wear,the continuous erosion of Cl~-in HCl on the passivation layer will cause the porosity of the passivation layer,so the protection effect of the passivation layer on the composite material is limited.Under different loading conditions,the friction coefficient of composites is the lowest at 15 N,and the wear mechanism is mainly adhesive wear.The greater the load,the greater the wear rate of the composite.At different rotational speeds,the friction coefficient and wear rate of the composites are the minimum when the rotational speed is 200 t/min,and the wear mechanism is mainly adhesive wear.The change of friction coefficient of rGO/TiCN-W-Cu composites is mainly affected by the continuous friction layer composed of oxide film,and the change of wear rate is mainly affected by the wear behavior. |
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