THE CHANGE IN MECHANICAL PROPERTIES AND MICROSTRUCTURE OF GREY CAST IRON DUE TO HEAT TREATMENT.

<p>Grey cast iron is a brittle or quasi-brittle material very sensitive to the microstructure morphology deriving from its solidification kinetics. This is the reason why different zones of a casting, even with the same thickness, may be characterized by different mechanical properties according to the solidification time. The mechanical characterization of the alloy made by following the Standards that refer to values obtained from separately casted samples is insufficient for a designer who needs to know the specific properties of the material in each zone of interest of the casting. In this work a method is described to predict the mechanical properties of castings made of GH 190 cast iron that correlates the solidification times with the ultimate tensile strength through a master curve, supposed to depend only on alloy chemical composition. This predictive approach was successfully validated with experimental mechanical characterization of a real industrial casting.</p>

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Comparative Experimental Study of Tribo-Mechanical Performance of Low-Temperature PVD Based TiN Coated PRCL Systems for Diesel Engine

Advances in Tribology ◽

10.1155/2018/9437815 ◽

2018 ◽

Vol 2018 ◽

pp. 1-12 ◽

Cited By ~ 2

Author(s):

Ghulam Moeen Uddin ◽

Muhammad Sajid Kamran ◽

Jawad Ahmad ◽

Muhammad Ghufran ◽

Muhammad Asim ◽

...

Keyword(s):

Mechanical Properties ◽

Cast Iron ◽

Low Temperature ◽

Cylinder Liner ◽

Ceramic Coatings ◽

Grey Cast Iron ◽

Tin Coating ◽

Ic Engine ◽

Trade Offs ◽

Grey Cast

Piston ring and cylinder liner (PRCL) interface is a major contributor to the overall frictional and wear losses in an IC engine. Physical vapor deposition (PVD) based ceramic coatings on liners and rings are being investigated to address these issues. High temperature requirements for applications of conventional coating systems compromise the mechanical properties of the substrate materials. In the current study, experimental investigation of tribo-mechanical properties is conducted for various titanium nitride (TiN) coated PRCL interfaces in comparison with a commercial PRCL system. Low-temperature PVD based TiN coating is successfully achieved on the grey cast iron cylinder liner samples. Surface roughness of the grey cast iron cylinder liner substrates and the thickness of TiN coating are varied. A comprehensive comparative analysis of various PRCL interfaces is presented and all the trade-offs between various mechanical and tribological performance parameters are summarized. Coating thickness between 5 and 6 micrometres reports best tribo-mechanical behaviour. Adhesion and hardness are found to be superior for the TiN coatings deposited on cylinder liner samples with higher roughness, i.e., ~ 5-micron Ra. Maximum 62 % savings on the COF is reported for a particular PRCL system. Maximum 97% saving in cylinder liner wear rate is reported for another PRCL system.

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