Ultrahard materials are essentially important as anvils for static high-pressure generation. Here the author reviews the use of various types of tungsten carbide and sintered polycrystalline diamond materials for higher pressure generation in Kawai-type Multi-anvil Apparatus (KMA). A recent attempt in high-pressure generation in KMA using nano-polycrystalline diamond anvils is also introduced with some future perspectives.
Tungsten carbide based hardmetals have been used for the cylinders and anvils of high pressure apparatus, because of their high hardness, compressive strength and Young's modulus. In this article, tungsten carbide based hardmetals used for each high pressure apparatus are reviewed. In addition, newly developed ultra-fine grained binderless hardmetal TJS01 is introduced.
Diamond anvil is an essential item for high-pressure experiment. We do a stocking of a natural diamond rough stone to produce the diamond anvil. We want to tell that difficulty of the stocking. In addition, we introduce laser machines and try for improvement of the cutting accuracy every day.
In this article, commercially available polycrystalline diamond (PCD) used in high pressure science including our newly developed materials are reviewed. Microstructure and physical properties of them are explained in relation to the binding strength between diamond particles. Neck growth of diamond is important to generate higher pressure. In addition, I notice several cautions when using PCD materials.
Pressurization systems used for high-pressure machineries are mainly categorized into two types: First is so-called “direct pressurization system”, in which volume of high-pressure vessel is directly reduced by piston. Second is so-called “indirect pressurization system”, in which pressure medium is injected into high-pressure vessel by pressure-intensifier pump. The former and latter systems are often used for food-pressurization and cold isostatic press machines, respectively. In this article, I introduce newly-created small-scale pressurization equipment and several large-scale machines provided by our corporation.
Pressure is, as same as heat, an important factor for various fields of science since it affects to physical properties and chemical reactions of all materials. Although pressure effects on the stability and function of biological molecules such as lipids, sugars, proteins, nucleic acids, and even on life itself, have been interested from early days, such approach did not popular for many researchers because it needed large-scale expensive apparatuses of specially designed. However, recent developments of small-size high-pressure optical cell units provide a real-time monitoring of pressure effects on such biomolecules under elevated pressure conditions using various techniques with commercially available spectrometers. In this article, recent advances and future challenges in the high-pressure research methods and apparatuses used for life and food sciences are reviewed.