Dry sliding wear of ductile and austempered ductile iron: effect of load and sliding speed

ABSTRACT

In this study, dry sliding wear behaviour of a copper alloyed austempered ductile iron (ADI) consisting of very fine ausferrite, small high carbon austenite blocks, was investigated against 100Cr6 ball using ball-on-disc tribometer. Tribotests were conducted at different loads of 10, 30, 50, and 100 N and speeds between 0.39 to 0.79 m/s. Worn-out surfaces and wear debris revealed tribe-oxidation and abrasive wear as the primary mechanism for material removal at lower loads and low speed (0.39 m/s). With an increase in load and speed, fragmented graphite nodules acted as solid lubricants. Additionally, partial transfer of tribo-oxide onto the counter-body ball, and plastic deformation and strain hardening of ADI matrix lowered the friction coefficient and wear rate at higher loads and speed, to nearly 1/3 and 1/10 as compared with those at lower loads and speed. The superior wear resistance of present ADI is worthy of consideration for transmission parts.

GRAPHICAL ABSTRACT

KEYWORDS:

• Austempered ductile iron
• ausferrite
• austenite
• graphite nodules
• tribology
• tribo-oxidation
• sub-surface
• strain hardening

Disclosure statement

No potential conflict of interest was reported by the author(s).

Author contributions

All authors contributed to the study’s conception and design. Material preparation, data collection and analysis were performed by Uma Batra, Sandan Kumar Sharma and Manpreet Singh. The first draft of the manuscript was written by Uma Batra and all authors commented on previous versions of the manuscript. All authors read and approved the final manuscript.

Shriya E: Testing, SEM images of surfaces and debris, Formal analysis, writing original draft.

Manpreet Singh: DI and ADI sample preparation, heat treatment of samples.

Uma Batra: Resources, Supervision, Validation, Writing – review and editing.

Sandan Kumar Sharma: Conceptualization, Methodology, Validation, Analysis and Investigation, SEM image analysis of worn surfaces and debris, Writing – review and editing.

Additional information

Funding

This work was supported by the Ministry of Steel – India funded project [grant number 11(6)/GBS/2019-TD].