Erosion Resistant Surface Coating

The combination of ultra-hardness with enhanced toughness provides excellent protection against erosion at various impingement angles.

Hard but brittle materials suffer from high erosion rates at angles close to 90 degrees. Ductile and tough metals which lack hardness are eroded more quickly at lower impingement angles of 30 degrees due to ploughing and cutting effects. In practical applications it is often difficult to prevent particles in turbulent fluid or gas flows from bombarding surfaces from various impingement angles. Hardide has shown consistently low erosion rates at different impingement angles due to the combination of hardness, toughness and compressive stresses.

Erosion resistance tests were performed in accordance with ASTM G76-95; velocity was 70m/sec and aluminium oxide (particle size 50 microns) was used as the erosive material. The graph below presents the test results and comparative results for other hard materials at various angles of impact. The Hardide erosion rate was 0.017 - 0.019 mm3/g which is significantly better than the erosion rate of the tested types of Cemented Carbide, White Iron, Hard Chrome and Chrome Carbide Weld Overlay. Hardide resists erosion by alumina particles at 70m/sec; three times better than steel and more than two times better than Cemented Carbide (hardmetal). Hardide also significantly exceeded various currently used hard materials in a sand/water erosion test.

Erosion by Alumina hard particles carried by gas jet at 70 m/sec
Angle of target, °	Erosion Rate, mm3/g*1000
	Hardide	Chrome Carbide Weld Overlay	White Iron	AR-500 Abrasion-resistant steel	WC cladding	Hard Chrome
45	19	71	76	53	36	25
60	18	66	64	48	41	26
90	18	60	40	40	50	30