WEAR PROPERTIES OF FE-FE3C NANOPHASE WHITE IRON OBTAINED BY MECHANOSYNTHESIS AND HOT ISOSTATIC PRESSING

Dry sliding weal tests were carried out on an Fe-Fe3C nanophase white iron, of composition 85Fe(3)C-15Fe (vol.-%), produced by mechanosynthe sis of powders and compaction. The tests were carried out using a flat on cylinder tribometer, with the specimens sliding against a ceramic Al2O3-TiO2 countermaterial under applied loads of 5, 10, 20, and 30 N and sliding speeds of 0.3, 1.2, and 1.8 m s(-1) for sliding distances up to 10 km. During the tests the coefficient of dynamic friction and total wear were recorded by means of a loading cell and a linear varia ble displacement transducer respectively. The depth of the wear tracks was recorded using a stylus profilometer and the worn surface was inv estigated by scanning electron microscopy (SEM). X-ray diffraction ana lysis and SEM observations were performed on the collected debris and the damage to the countermaterial was evaluated. For comparison, the s ame tests and analyses were carried out on a type T high speed steel a nd on a WC-TiC-Co composite. The Fe-Fe-3 C nanophase white iron underw ent mild sliding wear up to F = 10 N; the type T high speed steel show ed abrasive wear and the WC-TiC-Co composite showed both adhesive (low loads and sliding speeds) and abrasive (high loads and sliding speeds ) wear. From the observation of the maximum depth of the wear tracks m easured on the tested materials it can be noted that, at all speeds, t he wear resistance of the nanophase white iron against the Al2O3-TiO2 ceramic counterface up to F = 20 N is comparable to that observed for the T high speed steel tested in the same conditions. (C) 1998 The Ins titute of Materials.