Experimental study on the anti-fouling effects of Ni-Cu-P-PTFE deposit surface of heat exchangers

The purpose of the present study was to investigate the effect of the electroless Ni-Cu-P-PTFE deposit surface on anti-fouling of heat exchangers, which was considered as a way to mitigate the accumulation of mineral fouling in the heat exchangers. Electroless Ni-Cu-P-PTFE deposits with various PTFE content were prepared on mild steel (1015) substrate surface by different process parameters. Surface morphology and microhardness were investigated by using SEM, MH-6 Vickers, respectively. The results showed that the addition of PTFE particles into the Ni-Cu-P matrix hardly affected the microstructure of the deposits. Microhardness was decreased with the addition of PTFE in the deposits. Moreover, the surface free energy of Ni-Cu-P-PTFE deposits was decreased with the increase of PTFE particles in the deposits. Further fouling experiments indicated that the surfaces of Ni-Cu-P-PTFE deposits with different PTFE content inhibited the adhesion of fouling compared with the mild steel surface of the heat exchangers. The adhesion weight of fouling was approximately in inverse proportion with the addition of PTFE particles in the deposits, but not the value of surface roughnesss. The anti-fouling property can not be improved ideally even considering the option of making Ni-Cu-P-PTFE coatings smooth.