Effect of Halogen-Free Ionic Liquids as Additives of Biolubricants for Room Temperature Titanium-Steel Contact

The surface interactions and tribological behavior of titanium-steel contact have been previously studied under the application of several commercial Ionic Liquids (ILs). In certain cases, superior anti-wear characteristics have been experienced when lubricating using ILs. This is often attributed to the development of a protective tribolayer that forms during application. One anion in particular amide, [Tf2N], has exhibited these characteristics with particularly positive results. However, amide is an anion that contains halogens, which are toxic and can cause harm if not handled properly. Due to the toxicity of most lubricants there has been a growing need to transition to bio-lubricants due to their low impact to the environment. This particular work will investigate the use of Trihexyltetradecylphosphonium, [P6,6,6,14]-+, cation with anion decanoate [Deca] as a non-toxic alternative to amide [Tf2N]. [P6,6,6,14]-+[Deca] and [P6,6,6,14]-+[Tf2N] will be compared as additives (1.0 and 2.5 wt. %) in Coffee Bean oil (CB) for lubrication of titanium-steel contact at room temperature. In this work, tests are conducted using a ball-on-flat reciprocating tribometer as per ASTM G133 with lubricated titanium-steel contact. An AISI 420C stainless steel ball is used on a Grade 5 6Al-4V titanium alloy disk specimen. Friction and wear volume are measured, examined, and discussed.

Evaluation of Mechanical Properties of a Superalloy Disk with a Dual Microstructure

The main purpose of this paper is to evaluate the mechanical properties of a FGH96 alloy disk with a dual microstructure. FGH96 is a powder metallurgy (P/M) processed disk alloy, which was developed in the 1990s in China. The manufacturing processes used to produce the FGH96 disk with a dual grain structure consisted of atomization by plasma rotating electrode process (PREP), hot isostatic pressing (HIP), isothermal forge, special heat treatment for obtaining dual grain struc-ture and final heat treatment. The disk was cut up and completely evaluated. Mechanical properties, including tensile, stress rupture, plastic creep, low cycle fatigue, fatigue crack growth rate, fracture toughness, impact and hardness, were tested at room and higher temperatures. In addition, a detailed grain characterization of the disk, from rim to bore, was also presented.