Preparation And Application Of Electroless Ni-P-β-SiC Composition Coating On Aluminum Alloy

With the rapid development of aluminum alloy application, its disadvantag-es o f low hard ness, lo w wear re s is ta nce a nd eas y to oc cur inter crys ta l co rros io naffec t its app licatio n range s. Elec tro le ss co mpos ite plating is o ne o f the ne w typeme thod in the surface treatme nt o f a luminum a llo y, whic h ca n end ued good highwear re s is ta nce to s urface o f a luminum a llo y. So N i-P-β-SiC co mpos ite co atingshas bee n beca me rescarc h e mp has is,whic h aro used wide atte ntio n to by do mes it-ic and foreign scientists.In this pape r, Ni-P-β-SiC co mpo s ite coa tings was prepa red o n a luminumallo y s urface b y e lec tro le ssdepos ito n. The N i-P-β-SiC co mpo s ite co atingsmicros tructure was obse rved with the op tica l microscope, sca nning e lectronmicroscope (SEM).And p has e tra ns formatio n a nd the c he mica l co mpos itio n o fcompo s ite coa tings were a na lyzed with X-ray d iffractio n (XRD) a nd e ne rgydispers ive spe ctroscop y(EDS). The adhe s ive stre ngth o f coating was q ua ntita tiv-ely meas ured b y Type WS-2005coating ad hes io n scra tc h tes ter. The e ffec ts o fzinc immers io n process variab le o n the ad hes ive s tre ngth a re stud ied.Thehard nes s a nd dry frictio n a nd wear performa nc e o f N i-P-β-SiC co mpo s itecoating was s tud ied b y EM-1500L mic ro vicke rs hard nes s tes ter a nd HT-1000type high te mpe rature ba ll d isc fric tio n a nd wea r tester. Co nc lus io ns are asfollows:Tho ugh the proces s o f N i-P-β-S iC che mica l p lating co mpos ite coating o naluminu m a llo y p isto n we go t the bes t ba th formula a nd proce ss co nd itio ngs.Bes ides, it was co nfirmed that uniform coating depos ited o n co mp la x co npo ne ntsurface b y ro lling co mpos it p lating. The repo rt s ho wed tha t with the formula and pla ting para mete rs in this ar tica l to ge t the N i-P-β-S iC co mpos ite coating hadgood ad hes io n. β-S iC uniformly d istrib uted in the coating whose thick nes s wasabout30μ m and hardness was565HV.Thro ugh ortho go na l test, the impact o n coating a nd the s ubs tra te bond ingstre ngth b y vario us para me ters o f leac hing zinc proces s was obta ined. Theresults show that the most obvious influe nce on bonding strength is Zinc oxide.Fina lly ge t the be st leac hing zinc was A2B2C0D1E3which is that Zincoxide:45g/L, sod ium hydro xide:270g/L, fe rric c hlo ride:1.4g/L, sod ium pota ss i-um tartrate:14g/L, zinc d ipp ing time:20s, zinc withdra wa l time:10s, two times o fzinc dipping time:40s and the binding force of Ni-P coating was23.5NNi-P/Ni-P-β-SiC wa s prepared b y the optimized prepara tio n proce ss, whosemicros tructure, co mpo s itio n a nd phase s tructure was obse rved a nd a na lyzed andthe res ults s howed that the coa ting is pho spho rus coating whic h is a morp ho usstructure. The bo nd ing s tate is very we ll betwee n the coa tings a nd the s ubs trate..β-SiC was added to the coating whose hardness was increased, and the larger thepartic le s ize is，the higher the coating’s hard ness is.The hard ness is o f w2.5Ni-P-β-SiC is up to617HV0.05.The wearing capa c ity, frictio n coeffic ie nt, wea ring morp ho lo gy o f the co-ating wa s observed a nd a na lyzed. The hard ness a nd wea r res ista nce o f co mpo-s ite coa tings were mod ified b y β-S iC add ing to N i-P coating. W1.5a nd W2.5Ni-P-β-SiC co mpo s ite coating had exce lle nt wearing res ista nce, while the wear-ing resistance of W0.5Ni-P-β-SiC composite coating was poor.