Compound modifier

Abstract: In order to improve the performance of soft plantation wood, an environmentally friendly wood modifier was developed. First, using urea and melamine as crosslinking agents, the glucose-urea-melamine resin (MUG) was prepared with glucose under the catalysis of inorganic acid and metal ions. Then MUG, sodium silicate, and distilled water were mixed and stirred at 40 °C to prepare MUG resin/sodium silicate compound modifier (G20S10, G10S20, the subscript number represents the mass percentage of the component in the solution.). Then plantation poplar wood (Populus tomentosa) was impregnated and modified with them. Their physical and mechanical properties were tested and compared with those of the wood treated with sodium silicate of 20% mass fraction (S20). Infrared analysis showed that the amino resin characteristic structure (CO-NH-) existed in MUG, and the absorption peak of the furan ring (C=C) appeared. Compared with S20 modified wood, the shrinkage degree of G10S20 or G20S10 modified wood is reduced, their moisture absorption is decreased, and their dimensional stability is improved. MUG resin/sodium silicate compound modifier can effectively enhance the wood’s density, modulus of elasticity, modulus of rupture, and compression strength. SEM analysis showed that there were columnar and granular solid substances attached to the cell wall, cell lumen, intercellular space, and vessel of G20S10 modified wood. EDX showed that the number of Si elements on the cell wall was significantly increased compared with the control, indicating that the modifier effectively entered the wood cell wall. The G20S10 can greatly improve the wood’s physical and mechanical properties through an organic–inorganic compound synergistic effect. It is a green, non-formaldehyde, low cost wood modifier with broad application prospects.

Abstract: The invention discloses high-chromium cast iron which comprises the following chemical components in percentage by weight: 2.3%-2.7% of C, 14%-16% of Cr, 0.4%-0.6% of Mo, 0.3%-0.5% of Ni, 0.3%-0.5% of Cu, 0.8%-1.3% of Si, 0.6%-1.0% of Mn, not more than 0.04% of S, not more than 0.04% of P and the balance of Fe. A preparation method of the high-chromium cast iron comprises the following steps: smelting in a smelting furnace to form molten alloy, deoxidizing, adding 0.3%-0.6% of a compound inoculant and 0.1%-0.2% of a compound modifier based on the total weight of the molten alloy for inoculating and modifying for the first time, and pouring the molten alloy into a casting ladle for inoculating and modifying for the second time, wherein 0.2%-0.4% of the compound inoculant and 0.3%-0.6% of the compound modifier based on the total weight of the molten alloy are prearranged in the casting ladle, the compound inoculant is a Ti-V-CaO-BaCO3-Zn compound inoculant, and the compound modifier is a rare earth ferrosilicon alloy modifier. According to the preparation method, the recession resistance of an inoculation and modification structure can be improved, so that the high-chromium cast iron is relatively good in bending strength and wear resistance.

Abstract: Al–Si alloys are among the most popular casting metals. Two-component aluminium alloys with silicon are not suitable for direct use after melting. Subject to their silicon content, Al Si alloys have a coarse-grained eutectic phase, and alloys with more than 13% Si content also feature large crystallites or β-phase needles. The β-phase is hard, but also fragile. Large crystallites are good planes of division, and they reduce the mechanical properties of alloys.In this study, the Al-9% Si alloy was refined with a sodium modifier. The modifier was added to the mould by the in-mould method. The modifier's influence on the microstructure and mechanical properties of the alloy was presented graphically. The results of the analysis indicate that the compound modifier influenced the evaluated properties of the Al-9%Si hypoeutectic alloy.