Study On A Kind Of No-bake Phosphate Binder Used For Foundry

Foundry inorganic phosphate binders is a new cementing material which is said for aapplication prospect for its low gas evolution, good collapsibility, non-toxic andenvironmentally friendly. But phosphate binders storage is not stability and modelingprocess easier wicking which lead to its strength decreased rapidly in the process of use,and thus those disadvantage affect the use of it. In this paper, we develope a high-strengthcast from no-bake phosphate binder combining with the casting production requirementwhich can be used in casting production.First, we carries on the theoretical analysis of phosphate preparation process, the rawmaterials, formulation and preparation technology of the preparation of phosphate wasdetermined by the test. Then we prepare the modified phosphate binder by using B, C formodifying. From the orthogonal experiments, we can find that the modifier C is thesignificant influence factor performance on phosphate binder, and the modifier of B, water,phosphoric acid and Al(OH)3are the certain influence factoron phosphate binder. Thedosage ratio of raw materials for the above is:200g phosphate, aluminum hydroxide38g,B7g C4g,70g water.In order to obtain higher technological strength, we add single citric acid, oxalic acidand silane to research the influence of those on the binder. We find that the effect is betterwhen2g citric acid is added to the250g adhesive which can obtain0.98MPa tensilestrength; the effect is also better when4g oxalic acid is added which can obtain0.89MPatensile strength; and tensile strength of1.21MPa when added6drops of silane.In this paper phosphate binder is hardening by the method of self-hardening We usefused magnesia powder as a basis for curing agent, on the basis of it we make theexperimental research on the composite curing agent: Every12g curing agent zinc oxidecontains0.5g and0.5g magnesia powder, the24h tensile strength is0.95MPa; Every12gcuring agent containing2g ferroferric oxide and magnesia powder10g, the24h tensilestrength is0.97MPa; Every12g curing agent containing zinc oxide,1g ferroferric oxide and1g magnesia powder,10g effect is good, the24h tensile strength is up to1.55MPa, theoptimal formula of composite can be identified as curing agent ratio.Finally, we get more smooth surface castings, the preparation of phosphate self-hardening sand mold high strength, good pieces by conducting a production verificationtest. And we achieve the desired effect.