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Graphene, the two dimensional monolayer of carbon, is an essential building block for advanced electronic applications. Graphene is often integrated with bulk conductors, metals and semiconductors, for optoelectronic applications. The semimetal bismuth, that shares many electronic properties with these other conductors, is interesting because like graphene, it is a gapless conductor of high electronic mobility with linear dispersion relations and low electronic density. We studied the doping of graphene by Bi and the interfacial electric dipole.Graphene Raman spectroscopy results show that there is a very large charge transfer between graphene and bismuth. This doping is larger than in the interfaces of graphene with metals such as Cu and semiconductors such as Si. Our findings are in good agreement with recent theoretical results for graphene bismuth interfaces. We also present a demonstration of zerobias photocurrent generation that is enabled by the electric dipole at the graphene bismuth interface.

In minimum quantity lubrication (MQL), an aerosol containing a minimum amount of the cutting fluid is delivered to the tool/workpiece interface during the metal cutting operation. The fluid lubrication by the fluid and the cooling by the compressed air in the aerosol improves the cutting process, while the low consumption rate in MQL provides less cleanup and reduces the associated cost. In this paper, molybdenum disulfide (MoS2) and hexagonal boron nitride (hBN) nanoparticles were added to the aerosol for providing a third functionality to the MQL, which is solid lubrication at the interface. Both orbital drilling and tribological testing using a four-ball tester were studied to examine the effectiveness of solid lubrication in MQL. In orbital drilling of titanium with tungsten carbide tools, MQL with nanofluids containing MoS2 nanoparticles resulted in less transfer film buildup on the tool. In four-ball testing, MQL with nanofluids with MoS2 and hBN nanoparticles yielded lower surface temperatures and less variation of frictional torques in titanium.

Additive manufacturing (AM) has recently become an increasingly popular form of production due to its advantages over traditional manufacturing methods, such as accessibility, the potential to produce parts with complex geometry, and reduced waste. For the widespread industry adoption of AM components, metal AM has the most potential. The most popular methods of metal AM are powder-based manufacturing techniques. Due to the layer-by-layer nature of AM, the mechanical and tribological properties of an additive manufactured part differs from those of traditionally manufactured components. For the technology to develop and grow further, the tribological properties of AM components must be fully explored and characterized. The choice of material, surface textures, and post-processing methods are shown to have significant impact on friction and wear. Therefore, this paper focuses on reviewing the existing literature with an emphasis on the development of advanced materials for AM applications as well as the optimization of the resulting surface quality via post-processing and presents areas of interest for further examination in this prospective technology.