Generalized Wear Resistance Assessment Criteria

Generalized Wear Resistance Assessment Criteria

C Paul Qiao, Levi Kempka, Steve Schmitz, Joe Schreiner

L.E. Jones Company

Menominee, MI 49858

ABSTRACT

Pin-on-plate reciprocating wear test has been widely used for materials wear pair resistance evaluation such as for valvetrain components application. A standard Pin-on-Plate test method with Plint reciprocating test equipment was established more than 15 years ago at L.E. Jones (LEJ) Company. Compared to a dynamometer engine test, the Pin-on-Plate test method is much more cost effective and capable of simulating actual wear mechanism. Therefore, the lab type of wear resistance test method can significantly reduce the number of engine test runs for valvetrain design validation purpose. The classical LEJ Plint wear test criteria for materials’ wear resistance assessment include pin specimen wear, plate specimen wear and total materials wear. However, the wear test criteria do not show the relative wear from pin and plate which can be an important information for valvetrain component materials selection during an engine design.

The generalized wear resistance criteria has been recently established at LEJ with considerations of both actual amount of materials wear and eccentric wear propensity of a materials matching pair. The eccentric wear factor has been defined as the difference between pin specimen and plate specimen (W_pin-W_plate) in absolution value divided by total amount of mass loss of the pin and plate specimens. Hence, the Generalized Wear Resistance (WRA) Index can be defined as: WRA Index = |(W_pin-W_plate)|/W_total + W_total. The effect of different wear testing parameters on the testing criteria was also investigated in this study. Applying the generalized wear resistance criteria, wear resistance of a materials matching pair can be classified into three general categories namely, high wear resistant materials pair, acceptable wear resistant materials pair, and poor wear resistance materials pair for valvetrain component application and alike.