New Paradigm On The Mechanical Properties of In-Situ Formed By Al/TiB2 and Al/TiB2/Cu MMCs

In the current study, in-situ formed Al/6wt. % TiB2 and Al/6wt. % TiB2/4wt. % Cu Metal Matrix were investigated. Composites were made using the sir casting method, and both composites were compared. The composite is synthesized by combining two precursor salts, Potassium Hexa Fluro Titanate (KBF4) and potassium tetrafluoroborate (K2TiF6), with stoichiometric compositions corresponding to 6 percent by weight of TiB2 particles, with A356 aluminium melt at 820° C, speed 300 rpm, and holding time 30 minutes. Following that, 4wt. % Cu powder was added to the composite melt, which was then poured into the permanent mould. Mechanical properties tests such as tensile strength, hardness, and fracture toughness were carried out in accordance with ASTM guidelines. The mechanical properties of the in-situ formed Al/6wt. % TiB2/4wt. % Cu composite outperform those of the Al/6wt.% TiB2 composite and base metal. Optical micrograph and XRD analysis both confirm the presence of TiB2 and Cu particles.

Effect of plasticizers on the properties of sugar palm nanocellulose/cinnamon essential oil reinforced starch bionanocomposite films

This work examines the effects of plasticizer type and concentration on mechanical, physical, and antibacterial characteristics of sugar palm nanocellulose/sugar palm starch (SPS)/cinnamon essential oil bionanocomposite films. In this research, the preparation of SPS films were conducted using glycerol (G), sorbitol (S), and their blend (GS) as plasticizers at ratios of 1.5, 3.0, and 4.5 wt%. The bionanocomposite films were developed by the solution casting method. Plasticizer Plasticizers were added to the SPS film-forming solutions to help overcome the fragile and brittle nature of the unplasticized SPS films. Increasing plasticizer contents resulted in an increase in film thickness and moisture contents. On the contrary, the increase in plasticizer concentrations resulted in the decrease of the densities of the plasticized films. The increase in the plasticizer content from 1.5 to 4.5% revealed less influence towards the moisture content of S-plasticised films. For glycerol and glycerol-sorbitol plasticized (G and GS) films, higher moisture content was observed compared to S-plasticised films. Various plasticizer types did not significantly modify the antibacterial activity of bionanocomposite films. The findings of this study showed significant improvement in the properties of bionanocomposite films with different types and concentrations of plasticizers and their potential for food packaging applications was enhanced.

Effect of NaBr on the Structural, Thermal and Mechanical Properties of HPMC:NaBr Composite Films

The hydroxypropyl methylcellulose (HPMC):sodium bromide (NaBr) composite films were prepared using different concentrations by solution casting method. The crystalline percentage of the pure HPMC was reduced from 74% to 60% upon the incorporation of 0.7 wt.% of NaBr salt, which suggests that the NaBr salt disrupted the host polymer crystalline phase. The two-phase microstructure in the morphological images reflects the phase separation at different concentrations of dopant. The functional studies revealed the considerable variation of intensity and the shift of peaks due to the action of NaBr in the host polymer matrix. The HPMC showed a large increase in the glass transition temperature (Tg) from 65 ºC to 86 ºC and simultaneously reduction in the weight percent loss was observed. The mechanical analysis revealed that the added dopant has a significant effect on the mechanical properties of HPMC.

Study the effect of nitrogen content on the friction and wear properties of Zr-Cu-Ni-Al bulk metallic glasses

The effects of nitrogen on friction and wear properties of Zr-based bulk metallic glasses were investigated experimentally. Preparation of Amorphous Bars by copper mold suction casting method. XRD was used to characterize the structure of samples, which proved their amorphous structure. The surface properties of the samples were studied with a microhardness tester and a friction and wear tester. The wear surfaces of the sample were analyzed by scanning electron microscopy (SEM) and energy dispersive spectrometer (EDS). The results show that the introduction of nitrogen improves the hardness and wear resistance of Zr-based metallic glass. Compared with the non-N-doped Zr-based metallic glass, the N-doped Zr-based metallic glasses have higher hardness and lower wear rate. In particular, the sample with 1.5% nitrogen doping has the largest hardness (578.58hv) and the lowest wear rate (1.04 × 10−3mm3 N−1 m−1). The wear types of N-doped Zr-based amorphous on GCr15 are mainly abrasive wear and adhesive wear.

Effect of multiple forging on the microstructure and properties of an as-cast Cu–Ni–Si alloy with high Ni and Si contents

A Cu–Ni–Si alloy with high Ni and Si contents was prepared by the traditional melting and casting method, and then multiple forging and ageing were conducted to investigate their effect on the microstructure and properties. The results show that reticular Ni31Si12 phases are located on the grain boundaries of the dendritic α-Cu(Ni,Si) solution matrix in the as-cast Cu–Ni–Si alloy because of the high Ni and Si contents, and some rice-like Ni2Si phases precipitate in the interior of α-Cu(Ni,Si) grains during cooling. With increasing number of forging passes, the morphology of the α-Cu(Ni,Si) matrix changes from dendrites to elongated dendrites and then equiaxed grains, the Ni31Si12 phase changes from reticular to irregular and then particle-like, while the Ni2Si phase gradually disappears. As a result, the hardness increases continuously up to 18 forging passes, while the electrical conductivity first increases and then decreases significantly. The hardness and electrical conductivity achieve the highest values with 18 forging passes and a subsequent ageing treatment at 450 °C for 4 h, and the corresponding microstructure comprises an equiaxed α-Cu(Ni,Si) matrix with microscale Ni31Si12 particles and sub-microscale Ni2Si precipitates.

DEVELOPMENT OF TECHNOLOGICAL PARAMETERS FOR THE FORMATION OF FASTS BY THE SLIDING CASTING METHOD

The materials of the article consider the effectiveness of additives for stabilization and dilution of clay-free slippers. For theproduction of radio-transparent ceramic materials of Celsius-Willemite composition, the most efficient and energy-saving methodof production is the method of slip casting. According to the charge composition, this technology is complicated by the lack of claycomponents, which shows the need to use impurities to improve the rheology of such a slip. The main characteristics of aqueousceramic slippers are density, humidity, fluidity, viscosity, density factor, rate of mass accumulation. The slip must meet thefollowing requirements: be free from foam and gas inclusions, have satisfactory fluidity under low viscosity; be aggregativelystable (characterized by the absence of aggregation, coagulation and sedimentation of solid phase particles); have a high filteringcapacity to ensure fast and defect-free weight gain; to be chemically inert, to provide sufficient strength and low shrinkage of semifinished products, as well as the possibility of their easy release from the mold.