Research On Fabrication And Friction-wear Properties Of Fly Ash/Graphite/Aluminum Matrix Composites

Particle reinforced aluminum matrix composites have high strength and specific modulus while maintaining light weight.They are used in rockets,missiles,satellites and pistons of engines.Hybrid particle reinforcement can achieve good mechanical properties of composites,wear resistance,thermal properties,etc.,different reinforcement phases play their respective roles,meeting the requirements for structural and functional composite materials.This topic selects industrial waste fly ash and solid lubricant graphite particles mixed reinforced aluminum matrix composite material to play the role of enhancing the "wear resistance" and "reducing wear" of the particles,which not only improves the performance of the composite material,but also can powder Coal ash turns waste into treasure and reduces costs.In this paper,the fly ash/graphite/aluminum matrix composite with good wear resistance is prepared by powder metallurgy method.Firstly,the pre-treatment of granule fly ash and graphite is carried out by acid pickling and calcination,which effectively improves the reinforcement particles and aluminum alloy matrix.Wettability improves the affinity,compatibility and dispersibility between the reinforcing particles and the aluminum alloy.The ball milling mixture,forming pressure and sintering process were discussed to optimize the preparation process,density,hardness,phase reaction,microstructure,friction and wear properties and wear of fly ash and different content of graphite hybrid reinforced aluminum matrix composites.The mechanism isanalyzed and researched.The results show that:(1)After 6 hours of ball milling of the mixed powder,it was molded by pressing 40 MPa,sintered at 750? at a heating rate of 5?/min and kept for 1 h,and a relatively dense fly ash/graphite/aluminum matrix composite material was successful-ly prepared.When the sintering temperature is too high,the alloy is coarsened,causing over-burning.(2)Preparation of fly ash/graphite/aluminum matrix composites with lower density and higher hardness.The density of the composite decreases with the increase of graphite particles,the hardness first increases and then decreases,the hardness of the 10wt.%fly ash/4wt.%Gr/A16061(10FA/4Gr/6061)composite is 55.8 HV.(3)There is no other adverse phase in the fly ash/graphite/aluminum matrix composite prepared by powder metallurgy.The reinforcing particles are evenly distributed in the metal matrix,but the phenomenon of particle agglomeration occurs with the increase of graphite in the composite.There are many holes in the composite.(4)Graphite particles can effectively reduce the friction coefficient and wear of the composite.The friction and wear properties of the hybrid reinforced aluminum matrix composites are better than that of the single fly ash reinforced aluminum matrix composites.The wear of the composites follows the load and wear.The rotation speed increases and increases.(5)The wear mechanism of fly ash/graphite/aluminum matrix composites is dominated by abrasive wear and adhesive wear,and peeling wear occurs under high load.Figure [43] table [53] reference [94]...