The Tagnite coating provides abrasion resistance for magnesium sand castings, die-castings, extrusions and forging.  The coating has been used in the aerospace industry for over twenty five years by major aerospace firms such as Boeing, Rolls-Royce, Pratt & Whitney and Sikorsky Aircraft.

The table below illustrates data in the form of the number of cycles and a Taber Wear Index (TWI).  The data shows that the Tagnite coating on both AZ91D and ZE41A is considerably more wear resistant than either HAE or Dow 17.  Though the abrasion resistance will be largely dependent upon the chemical nature of the coating, the significant increase in resistance is due to the TAG coating process in which the localized high temperature, occurring during the spark deposition, fuses the silicate and oxide species onto the metal substrate surface.

SampleTWICycleComments
AZ91D, TAGNITE, 0.3 mil95000<10% metal exposed
AZ91D, TAGNITE, 0.6 mil87000<10% metal exposed
AZ91D, TAGNITE, 0.8 mil75000<10% metal exposed
AZ91D, TAGNITE, 0.9 mil66000<10% metal exposed
AZ91D, HAE, Type I(0.2 mil)1427510 % metal exposed
AZ91D, HAE, Type II (2.6 mil)142180010% metal exposed
ZE41A, TAGNITE, 0.2 mil6100010% metal exposed
ZE41A, TAGNITE, 0.5 mil7500010% metal exposed
ZE41A, TAGNITE, 0.6 mil14500010% metal exposed
ZE41A, TAGNITE, 0.8 mil12700010% metal exposed
ZE41A, TAGNITE, 1.0 mil14900010% metal exposed
AZ91D, TAGNITE, 0.5 mil143000bare metal starting to show
AZ91D, Treatment 17, 1.0 mil371000coating gone after 500 cycles
AZ91D, HAE, 1.0 mil1041000coating gone after 50
Table Wear Index (TWI) defined as TWI+ (A-B)x1000/C where A is the weight of the test specimen before abrasion in milligrams, B is the weight of the test specimen after abrasion in milligrams and C is the number of cycles of abrasion recorded. Data provided by R.W. Murray, the DOW Chemical Company, Lake Jackson Research Center, Freeport, Texas.