8096 J Mater Sci(2006)41:8093-8100 Fig 3 Solids content in fresh b90 deposit of um-siC as a solids content in pH 2.8 function of(a)-PH and(b) suspensions: 50 wt% solids content in starting ns;deposition rate as a function of (c)-pH and (d)-solids content in the uspensions;electrical current change during the deposition as a function of (e)-pH and (f-solids content(60V,steel starting electrode; suspension in(a), (e),(e): 50 wt. solids: suspensions in(b),(d),(e) 56789101112 60 Solids content in suspension(wt c25 E巴E 23456789101112 5060 solids content (%) o30% o pH5 △60% 70% 可 time [min time [min From Fig 3c it is obvious that the rate of deposition In the next set of experiments, the effect of the from the suspension with pH 2.8 was slightly lower solids content in the starting suspension was verified than that at the natural pH 5. The deposit formed at for the deposition of suspensions with 30-70 wt. of the cathode and appeared to be much firmer in the um-SiC powder at a constant pH value of 2.8 comparison to the deposit formed at the natural ph. Figures 3b and d reveal that the density of the deposits Its density was 1.78 g/cm, which is significantly higher as well as the deposition rate increased with ar than the starting suspension, i.e., 1.26 g/cm. The solids increase in the powder content in the starting suspen content in the deposit was determined to be 72.3 wt % sion On the other hand, the effect of the solids content i.e., 40.1 vol %(Fig. 3a). on the initial current in the suspensions, reflecting their 2 SpringerFrom Fig. 3c it is obvious that the rate of deposition from the suspension with pH 2.8 was slightly lower than that at the natural pH 5. The deposit formed at the cathode and appeared to be much firmer in comparison to the deposit formed at the natural pH. Its density was 1.78 g/cm3 , which is significantly higher than the starting suspension, i.e., 1.26 g/cm3 . The solids content in the deposit was determined to be 72.3 wt.%, i.e., 40.1 vol.% (Fig. 3a). In the next set of experiments, the effect of the solids content in the starting suspension was verified for the deposition of suspensions with 30–70 wt.% of the lm-SiC powder at a constant pH value of 2.8. Figures 3b and d reveal that the density of the deposits as well as the deposition rate increased with an increase in the powder content in the starting suspen￾sion. On the other hand, the effect of the solids content on the initial current in the suspensions, reflecting their 30 40 50 60 70 80 90 1 2 3 4 5 7 9 10 11 12 pH Solids content in deposit (%) solids content in suspensions: 50 wt. % starting suspensions 30 40 50 60 70 80 90 30 40 50 60 70 80 Solids content in suspension (wt.%) starting suspensions pH 2.8 Solis content in deposit (%) 0 0.5 1 1.5 2 2.5 1 2 3 4 5 7 9 10 11 12 pH Deposition rate (g/min) 0 0.5 1 1.5 2 2.5 0 10 20 30 40 50 60 70 80 solids content (%) Deposition rate (g/min) 6 8 6 8 0 1 2 3 4 5 0 5 10 15 time [min] pH2.8 pH5 pH11 current (mA) 0 1 2 3 4 5 0 5 10 15 time [min] 30 % 50 % 60 % 70 % current (mA) a c e f d b Fig. 3 Solids content in fresh deposit of lm-SiC as a function of (a) - pH and (b) - solids content in starting suspensions; deposition rate as a function of (c) - pH and (d) - solids content in the suspensions; electrical current change during the deposition as a function of (e)- pH and (f) - solids content (60 V, steel electrode; suspension in (a), (c), (e): 50 wt. % solids; suspensions in (b), (d), (e): pH 2.8) 8096 J Mater Sci (2006) 41:8093–8100 123