Study On Preparation And Application Vitrified Agglomerated White Fused Alumina Abrasives Of Bond

In response to the problem that conventional single-grain white fused alumina（WA）abrasives can not balance grinding efficiency and grinding quality,this paper prepared a kind of agglomerated white fused alumina（AWA）abrasives with high strength,high impact toughness,high grinding efficiency and grinding stability by using the aging relationship between holding time and interfacial solid solution.The influence of sintering process on the microstructure and mechanical properties of AWA abrasives was systematically investigated,and comparative grinding test s were conducted with single-grain white corundum abrasives for processing GH4169high-temperature nickel-based alloy.At the same time,AWA abrasives were applied to the light-curing resin bonded grinding pads.The preparation process of the light-curing AWA abrasive pads was systematically discussed,and the effects of the content of pore-forming agent and light-curing resin on the grinding performance and surface morphology of fixed abrasive pads（FAPs）were investigated by grinding experiments.（1）a small amount ofβ-Al₂O₃（Na₂O·11Al₂O₃）in WA abrasives could partially dissolve into the Si O₂-B₂O₃-Al₂O₃-Li₂O-Na₂O-Ba O low temperature ceramic bond during the sintering process,and the Al₂O₃infiltration phenomenon occurred at the interface between WA particles and vitrified bond,which led to the precipitation of a large amount ofβ-spodumene and monoclinic celsian in the vitrified bond and transformed the simple mechanical bonds between the WA particles and the vitrified bond into stronger chemical bonds.After sintering at 760℃for 4h,there was an excellent interfacial bonding state between the WA particles and the bond,and the cutting edges of the WA particles were at a suitable height.（2）After the vitrified bond bond and 240#WA particles were sinter ed at 760°C for 4h,the obtained AWA abrasives had uniform pore distribution,smaller pore sizes,porosity and density of 28.36%and 2.3534g/cm³.The compressive strength and impact toughness reached the maximum values of 26N and 63%,and the grinding ratio of AWA abrasive tool and the surface roughness of workpiece were 3.3 and0.333μm respectively.Compared with the WA abrasive tool under the same conditions,the grinding ratio was increased by 17.9%and the workpiece surface roughness was reduced by 21.1%.（3）The fixed AWA abrasive pads was prepared by UV curing method with AWA abrasive sintered at 760℃for 4h as abrasive,polyurethane acrylate light-curing resin as resin bond,expanded perlite powder as pore forming agent,tetrahydrofur an as adhesive,PET film and non-woven fabric as substrate.When the content of tetrahydrofuran is 3wt.%,the content of expanded perlite powder is 2wt.%,the content of light-curing resin is 43wt.%,and the content of AWA abrasives is 57wt.%,the surface morphology and comprehensive performance of prepared light-curing resin-bonded AWA abrasive pad at UV curing power of 2 kw and curing time of 3min are the best.The hardness,grinding efficiency and wear rate of the FAPs were 60HRB,0.238g/s and 0.115g/s respectively,and the average surface roughness and maximum peak-valley difference of the machined GH4169 high-temperature nickel-based alloy workpiece were 0.228μm and 6.271μm respectively.