Liquid Nitriding

Liquid nitriding is a subcritical surface enhancement process with one of the longest track records of success of any case hardening technology.

PVD Coatings

PVD coatings involve the deposition of thin (2-10 microns; 0.0001" – 0.0004") films on the surface of tools and components.

Engineered Bushings

HEF bushings are recognized worldwide for their excellent frictional and anti-seizure properties, and ability to withstand high loads.

Power Cell Components

Piston Pins

Piston Pins are subject to high loads and lubrication conditions that are far from optimal. HEF's family of DLC based CERTESS coatings have successfully demonstrated (a) friction loss reduction of up to 50%; (b) extended hydro-dynamic domain; (c) excellent scuff resistance and (c) significant increase in the load bearing capacity before seizure. The application of these coatings on free-floating piston pins in high power density engines allows for the elimination of the connecting rod bronze bushings and the possibility of utilizing a thinner connecting rod - both these factors lead to weight reduction and cost savings, while at the same time significantly reducing friction losses and enhancing piston pin durability.

Piston Rings

It is well known that 25% of the total friction losses in an engine are attributable to the piston ring pack - which accounts for 4% of vehicle's total fuel consumption. Friction reduction has to go hand-in-hand with scuffing and wear resistance. These performance demands and operating conditions make PVD coatings and specifically, carbon-based coatings an excellent choice for piston rings.

HEF offers three different PVD/PECVD coating options for piston ring applications. These options include:

Thick (20 microns) Chromium Nitride
- Chromium Nitride coatings are about 75% harder and have 30% lower coefficient of friction compared to conventional hard-chrome plated piston-rings. Hence, the chromium-nitride rings are more durable and the offer lower friction losses than conventional or nitrided rings.
- These Chromium Nitride coatings are deposited using a cathodic arc PVD process - which can deposit thick PVD coatings with minimal internal stresses.
Hydrogenated DLC
- These DLC coatings are about 50% harder and under lubricated friction coefficient that is 20% lower than chromium nitride coatings.
Hydrogen-free tetrahedral DLC
- a. Hydrogen-free DLC coatings are about 50% harder than hydrogenated DLC coatings - which gives them a somewhat superior wear resistance.

HEF can provide all the three coatings mentioned above - specific customer needs, operating conditions and powercell component design - all these factors play a role in coating selection.