Study On Carbon Nanospheres/Ni-alloy Composite Powder Laser Cladding Material Microstructure And Properties

Based on laser cladding processing of nickel base alloy powder materials and the related research results about various performance of cladding layer material from home and abroad,meantime explore the point could be optimized and innovated in the field,propose an innovative idea that introduce carbon nanospheres into Ni60 fluxed nickel base alloy powder and doing laser cladding experiments on surface of high temperature nickel base alloy GH3039 basis material.Using advantages of laser cladding in materials processing,with properties and nanometer characteristics of three-dimensional carbon nano-materials as the starting point,explore the nickel base alloy property change caused by carbon nanospheres.The experiment use the method of comparative experiments to explore the research content,totally set six groups contrast group.The major work and results as follow.Firstly according to the principle of micro/nano powder mechanical composite explore the adding quantity and method of carbon nanospheres,obtained an effective preparation method of high dispersive composite powder.Next on the basis of advantages and disadvantages of each powders presetting method,obtained a new method that integrate adhesive bonding and tabletting with mass experiments,prepare high quality laser cladding layer powder preset.Meantime,with large of experiments to optimize the laser cladding processing parameters get the high quality composite powder laser cladding layer sample.The main phase composition of Ni60 alloy cladding layer are ?-Ni??-Fe?CrB?Cr7C3 and Ni3Fe,the microstructure present the typical hypoeutectic characteristics.After adding suitable amount of carbon nanospheres,there are Fe3C,Cr23C3 and C phase appear in cladding layer,microstructure is still hypoeutectic characteristics,but y-Ni dentrite grain gradually refining,uniform,interdendritic eutectic organization populations increase.With the increasing amount of additive,mesh skeleton structure appear in cladding layer.Carbon nanospheres uniformly dispersed in the grain boundary and grain with low adding amount,but with the increase of adding amount,carbon nanospheres will reunite,cause negative impact to cladding layer.By analyze the test results,the microhardness of compound powder cladding layer are improved obviously,will increase with increase of carbon nanospheres adding amount,when adding amount is 3%can reach 1200HV.Aspect of antifriction,friction coefficient of cladding layer get minimum when adding amount is 1%,antifriction is best;Adding amount is 2%wear resistance get maximum.Cladding layer of high temperature oxidation property enhanced slightly with adding amount is 0.2%,but overall carbon nanospheres will cause negative impact to high temperature oxidation property of cladding layer.