Seizure behaviour of manganese phosphate coatings according to the process conditions

Surface and Wear Analysis of Zinc Phosphate Coated Engine Oil Ring and Cylinder Liner Tested with Commercial Lubricant

“…In contrast to other additives, detected sulphur additive on the ring and cylinder surfaces originating from lubricant was raised in the worn area of ring surface. Hivart et al and Pokorny et al showed in their research that the phosphate coatings do not exhibit intrinsic lubricating properties but can absorb and hold a considerable quantity of lubricant by virtue of their porosity [22,23]. However, no porosity was detected in the present study after the surface observations.…”

The effects of niobium and nickel on the corrosion resistance of the zinc phosphate layers

“…Besides the chemical accelerator other additives are used to afford other [7,[32][33][34][35], manganese ions [19,21,23,30,[35][36][37], tartaric acid [8,15], fluoride ions [8,[14][15][16]27,29], nickel ions [1,16,19,28,30,32,38], copper ions [39] molybdenum ions [15,37] and, more recently, niobium [39]. The present work aims to evaluate the viability of nickel substitution by niobium in zinc phosphate baths, as an environmental friendly alternative to the commercial phosphating processes usually adopted.…”

Degradation and crystalline reorganization of hureaulite crystals during the manganese phosphating of a high strength steel

“…This stage promotes a pH increase in the bath due to the hydrogen evolution reaction (HER); 2) amorphous precipitation, involving the massive precipitation of extremely fine phosphate crystals; 3) crystallization and growth; and 4) crystalline reorganization, i.e. the phosphate in the coating dissolves and re-precipitates at a very high rate which reduces the porosity and the exposed area [10,11]. This model, proposed initially for the zinc phosphating system, has been also accepted for the manganese phosphating system and is commonly seen as a sequential process that ends at stage four.…”