Beef tallow injection matrix for serial crystallography

Serial crystallography (SX) enables the visualization of the time-resolved molecular dynamics of macromolecular structures at room temperature while minimizing radiation damage. In SX experiments, the delivery of a large number of crystals into an X-ray interaction point in a serial and stable manner is key. Sample delivery using viscous medium maintains the stable injection stream at low flow rates, markedly reducing sample consumption compared with that of a liquid jet injector and is widely applied in SX experiments with low repetition rates. As the sample properties and experimental environment can affect the stability of the injection stream of a viscous medium, it is important to develop sample delivery media with various characteristics to optimize the experimental environment. In this study, a beef tallow injection matrix possessing a higher melting temperature than previously reported fat-based shortening and lard media was introduced as a sample delivery medium and applied to SX. Beef tallow was prepared by heat treating fats from cattle, followed by the removal of soluble impurities from the extract by phase separation. Beef tallow exhibited a very stable injection stream at room temperature and a flow rate of < 10 nL/min. The room-temperature structures of lysozyme and glucose isomerase embedded in beef tallow were successfully determined at 1.55 and 1.60 Å, respectively. The background scattering of beef tallow was higher than that of previously reported fat-based shortening and lard media but negligible for data processing. In conclusion, the beef tallow matrix can be employed for sample delivery in SX experiments conducted at temperatures exceeding room temperature.

The Microstructure and Property of a Titanium-Carbon Steel Clad Plate Prepared Using Explosive Welding

The microstructure and properties of pure titanium (Ti)-carbon steel clad plate prepared using explosive welding were characterized. The bonding of the welding interface was inspected using C-scanning imaging technique. The microstructure and composition of the clad were characterized with optical microscopy and scanning electron microscopy. Mechanical and corrosion properties of the clad plate were investigated using tensile test, shearing test, and potentiodynamic polarization measurement. The results show that the pure titanium and carbon steel plate are joined successfully without visible defects. The interface wave is uniform. SEM observation and EDS analyses show that some melt blocks distribute at the interface waves vortices. Hardness testes results show that after heat treating, the hardness values in the titanium layer of the clad plate are similar to the original titanium plate, whereas the values at carbon steel layer increase from the interface to 300 μm away. Tensile and shearing test results indicate that the mechanical properties of the clad meet the requirements of ASTM B898 standard. Corrosion test shows that the Ecorr of the clad plate is more positive, and icorr is 1 order of magnitude lower compared to carbon steel material, suggesting that the corrosion resistance of clad plate is better than that of carbon steel material. These results suggest that the clad plate has good bonding quality and properties to meet the processing requirement and can be safely applicable in the petrochemical field.

A Study on High Strength, High Plasticity, Non-Heat Treated Die-Cast Aluminum Alloy

The non-heat-treated, die-cast aluminum alloy samples were prepared meticulously via die-casting technology. The crystal structure, microstructure, and phase composition of the samples were comprehensively studied through electron backscatter diffraction (EBSD), metallographic microscopy, spectrometer, and transmission electron microscopy (TEM). The microhardness and tensile properties of the samples were tested. The die-cast samples were found to have desirable properties by studying the structure and performance of the samples. There were no defects, such as pores, cold partitions, or surface cracks, found. The metallographic structure of the samples was mainly α-Al, and various phases were distributed at the grain boundaries. Before heat treating, α-Al grains were mainly equiaxed with a great number of second phase particles at the grain boundaries. After heat treating, the α-Al grains were massive and coarsened, and the second phase grains were refined and uniformly distributed, compared with those before the heat treating. The EBSD results showed that the grain boundary Si particles were solid solution decomposed after heat treatment. The particles became smaller, and their distribution was more uniform. Transmission electron microscopy found that there were nano-scale Al-Mn, Al-Cu, and Cu phases dispersed in the samples. The average microhardness of the samples before heat treating was 114 HV0.1, while, after the heat treating, the microhardness reached 121 HV0.1. The mechanical features of the samples were tremendous, and the obtained die-cast aluminum alloy had non-heat-treatment performance, which was greater than the ordinary die-cast aluminum alloys with a similar composition. The tensile strength of the aluminum alloys reached up to 310 MPa before heat treatment.

Influence of Alkali Activator Type on the Hydrolytic Stability and Intumescence of Inorganic Polymers Based on Waste Glass

The main objective of this study is the synthesis and characterization of low cost alkali-activated inorganic polymers based on waste glass (G-AAIPs) using a mixture of NaOH and Ca(OH)2 as alkali activators, in order to improve their hydrolytic stability. This paper also presents detailed information about the influence of composition determined by X Ray Diffraction (XRD), microstructure determined by Scanning Electronic Microscopy (SEM) and processing parameters on the main properties of G-AAIP pastes. The main factors analyzed were the glass fineness and the composition of the alkaline activators. The influence on intumescent behavior was also studied by heat treating of specimens at 600 °C and 800 °C. The use of Ca(OH)2 in the composition of the alkaline activator determines the increase of the hydrolytic stability (evaluated by underwater evolution index) of the G-AAIP materials compared to those obtained by NaOH activation. In this case, along with sodium silicate hydrates, calcium silicates hydrates (C-S-H), with good stability in a humid environment, were also formed in the hardened pastes. The highest intumescence and an improvement of hydrolytic stability (evaluated by underwater evolution index and mass loss) was achieved for the waste glass powder activated with a solution containing 70% NaOH and 30% Ca(OH)2. The increase of the waste glass fineness and initial curing temperature of G-AAIPs have a positive effect on the intumescence of resulted materials but have a reduced influence on their mechanical properties and hydrolytic stability.

Cooling process optimization during hardening steel in water polyalkylene glycol solutions

Objects of investigations are water solutions of polyalkylene glycol (PAG) which are used as the quenchants in the heat-treating industry. They are tested by standard cylindrical probe made of Inconel 600 material. The main and not solved yet is the problem of transition from data achieved for standard probe to data suitable for any form and size of real steel part. It opens possibility to make predictable calculations. Taken this into account, it has been investigated water solutions of PAG of different concentration. It is underlined that cooling intensity of quenchant can be evaluated by Kondratiev number Kn. The mentioned number Kn varies within 0≤Kn≤1 when generalized Biot Biv number varies within 0≤Biv≤∞. As a main achievement of investigation is established correlation between standard Kn number and Kn number of real steel part. In many cases, when film boiling is absent, the established correlation is a linear function. It allows optimizing quenching processes: obtain high surface compressive residual stresses, save alloy elements and improve environment condition. All of this is achieved by tolerating chemical composition of steel with size and form of quenched object as it is proposed by UA Patent No. 114174. Also, the number Kn allows interruption of quench process when surface compressive residual stresses are at their maximum value that essentially improves the quality of steel components. Moreover, interrupted cooling prevents quench crack formation, decreases distortion of quenched steel parts. The results of investigations can be used by engineers in the heat-treating industry and scientists for further research.

RAFFMETAL EN AB-Al Si7Mg0.6 (EN AB-42200)

Raffmetal EN AB-Al Si7Mg0.6 (EN AB-42200) is a heat-treatable, Al-Si-Mg casting alloy in ingot form for remelting. It is used extensively for producing sand, permanent mold, and investment castings for applications requiring a combination of excellent casting characteristics, high strength with good elongation, and good corrosion resistance. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties. It also includes information on corrosion resistance as well as casting, heat treating, machining, and joining. Filing Code: Al-483. Producer or source: Raffmetal S.p.A.

DEUTSCHE EDELSTAHLWERKE CRYODUR 2243

Deutsche Edelstahlwerke Cryodur 2243 is a high-carbon, chromium-silicon-vanadium alloy cold-work tool steel that is suitable for applications requiring a combination of high strength, high toughness, and good wear resistance. This datasheet provides information on composition, physical properties, hardness, and elasticity. It also includes information on casting and heat treating. Filing Code: TS-821. Producer or source: Deutsche Edelstahlwerke Specialty Steel GmbH & Co.

SMITHS Ti-6Al-2Sn-4Zr-2Mo-Si

Smiths Ti-6Al-2Sn-4Zr-2Mo-Si is a near-alpha titanium alloy that was developed for use at elevated temperatures. It exhibits high strength and toughness, excellent creep resistance, and high temperature stability at temperatures up 550 °C (1020 °F). This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties. It also includes information on corrosion resistance as well as casting, heat treating, and joining. Filing Code: Ti-185. Producer or source: Smiths Metal Centres Limited.

VDM NICKEL 200

VDM Nickel 200 is an unalloyed nickel grade that contains at least 99.2% nickel. It has characteristics that are useful in several fields, notably chemical processing and electronics. This datasheet provides information on composition, physical properties, elasticity, and tensile properties. It also includes information on corrosion resistance as well as casting, heat treating, machining, and joining. Filing Code: Ni-778. Producer or source: VDM Metals GmbH (a subsidiary of Acerinox, S.A.).