73results about How to "Improve mechanical properties at room temperature" patented technology

The invention discloses a high-strength and heat-resistant magnesium alloy containing two rare earths. The high-strength and heat-resistant magnesium alloy containing the two rare earths comprises the components as follows: 14.0-17.0wt% of Y rare earth, namely Gd, Y and Er, 0.5-2.5wt% of Ce rare earth, namely one or several of La, Ce, Pr, Nd and Sm, 0.3-1.0wt% of Zr, impurities and the balance of Mg, wherein Gd is 11.0-15.0wt%, Y is 0.5-4.0wt% and Er is 0.5-2.0wt%; the content of Nd and Sm elements is 0.2wt% or less of the total amount of the magnesium alloy, or 0; the impurities including Fe, Si, Mn and a small amount of chloride; Fe is less than or equal to 0.002wt %, Si is less than or equal to 0.04wt%, Mn is less than or equal to 0.02wt%, and chloride is less than or equal to 0.002wt%; the impurity content is more than 0; Er in the Y rare earth can be replaced by one or several of Tb, Dy, Ho, Yb and Tm. The magnesium alloy has relatively high mechanical properties at room temperature and relatively stable high temperature creep resistance, and has relatively high yield rate of rare earth elements in the smelting process.

The invention relates to a process for manufacturing the molybdenum based rare earth alloy plate and equipment for manufacturing the same, wherein pure molybdenum powder is simultaneously added with four rare earth oxides of ZrO2, Y2O3, La2O3 and Nd2O3 according to certain ratio, by utilizing the chrematistics of long and large crystal grain and strong sag resistance and anti-creep property of rare earth alloy elements and the dispersion strengthening function, the re-crystallization temperature of the metal molybdenum is increased, the mechanical performances of the molybdenum based material such as tensile property, yielding behavior and extensibility are improved, and the application range of the molybdenum based material is widened; and the manufacturing process comprises production procedures of material preparation treatment, mixing treatment, forming treatment, sintering treatment, material making treatment and the like and the setting of various technical parameters of special technical equipment and process. With the preparation process, the molybdenum based rare earth alloy plate which has the advantages of good electric conductivity and heat conductivity, excellent high-temperature resistance and corrosion resistance and better mechanical performances such as tensile property, yielding behavior and extensibility, and fills in domestic blank and can replace the imported material can be manufactured.

The invention relates to an anti-erosion iron runner castable for a large blast furnace. The material comprises, according to weight percentage, 58-64 parts of compact brown fused alumina particles, 2-5 parts of white corundum particles, 16-23 parts of silicon carbide, 5-7 parts of aluminum oxide micro-powder, 2-3 parts of pure calcium aluminate cement, 2-3 parts of silicon dioxide micro-powder, 1.5-2.5 parts of spherical asphalt particles, 0.5-1.2 parts of carbon black powder, 1.5-3.5 parts of metal silicon powder, 0.2-0.6 part of boron carbide, 0.1-0.2 part of metal aluminum powder, 0.15-0.2part of a water reducing agent, 0.6-1 part of an anti-erosion agent and 0.05-0.08 part of explosion-proof fibers. According to the castable, the service life of a primary runner of a main runner is prolonged, and the stability of safe operation of an iron runner is improved. It is verified that the requirements for rapid baking without cracking, erosion resistance, oxidation resistance, slag adhesion resistance and iron flux can be met, the iron flux can reach 180000 tons or above without repairing, and good application prospects are achieved.

The invention relates to a high-strength magnesium alloy tube containing the following components in percent by weight: 7.8%-9.2% of aluminum Al, 0.2%-0.8% of zinc Zn and 0.2%-0.5% of manganese Mn. The high-strength magnesium alloy tube is characterized by also containing 0.5%-2.0% of rare earth RE in percent by weight. Because the rare earth RE can react with the aluminum Al to generate an Al-RE compound, the dispersion-strengthening function of the Al-RE compound can improve the strength of alloy and refine crystal particles so that the amount of a Mg17Al12 phase in the alloy is reduced, the original continuous and semi-continuous net-shaped crystal boundary structure is gradually changed into an interrupted and dispersion-distribution belt-shaped structure so that the fine crystal strengthening and the crystal boundary strengthening are more obvious, and meanwhile, the rare earth RE has the function of strong solid-dissolving strengthening, and the comprehensive mechanical properties of the alloy at room temperature are improved.

The invention provides a high-strength/toughness and high-stability cast aluminum magnesium alloy material. The material comprises the following components in percentage by mass: 9.3-9.8% of Mg, 1.3-1.5% of Zn, 0.2-0.4% of Ca, 0.2-0.4% of Ti, 0.2-0.5% of Ce, 0.1-0.15% of Sr, Fe not more than 0.15%, Ni not more than 0.03%, Cu not more than 0.06%, Si not more than 0.1%, Mn not more than 0.01%, and the balance is Al. The obtained aluminum magnesium alloy material is excellent in room-temperature mechanical property, excellent in natural aging stability and harmless in alloy components.

The invention discloses high-thermal-conductivity die-casting magnesium alloy and a preparation technology thereof. Chemical components of the high-thermal-conductivity die-casting magnesium alloy comprise, by mass, 8-13% of Zn, 0.1-1% of Ca, 0-1% of Mn, 0-1% of La, 0-1% of Ce and the balance Mg, wherein the content of Mn, the content of La and the content of Ce are not zero at the same time. The magnesium alloy is suitable for die casting and has excellent mechanical properties and high thermal conductivity, the thermal conductivity of the magnesium alloy at room temperature can reach about two times that of commonly used die-casting AZ91, and the tensile strength of the magnesium alloy is similar to that of AZ91 magnesium alloy.

The invention discloses a rare earth alloying Al-Cu-Mg-Fe-Ni high-strength and heat-resistance aluminum alloy. The aluminum alloy comprises the following components in percentage by weight: 2.6-3.5% of Cu, 1.3-1.8% of Mg, 0.1-0.8% of Fe, 0.1-0.8% of Ni, 0.05-0.5% of Nd, 0.1-0.25% of Mn, and 0.1-0.25% of Zr. Through mutual matching and combined actions of high Cu, low Fe, Ni and rare earth Nd, the room-temperature mechanical performance and high-temperature heat resistance of the alloy are synchronously improved, and the alloy obtains excellent comprehensive performance.

The present invention provides one kind of composite grain refiner for Mg-Al alloy and its preparation process. The composite grain refiner has the chemical composition including C 5-15 wt%, calcium 2.8-28 wt% or Ce 3-6 wt%, and Al for the rest. Its preparation process includes the following steps: mixing aluminum powder and carbon powder; pressing into block and stoving, setting inside corundum crucible and covering with refractory powder, isothermal treatment inside a box-type resistance furnace at 1000-1200 deg.c for 30-120 min to prepare intermediate Al-Al4C3 alloy, and remelting together with aluminum ingot and intermediate Al-70 %Ca or Al-10 %Sr alloy to prepare Al-Al4C3-Ca/Sr as composite grain refiner finally. The composite grain refiner can fine grains of Mg-Al alloy obviously.

The invention relates to a tantalum pentoxide modified molybdenum disilicide-based composite material and a corresponding preparation method, wherein, the preparation method comprises following steps: equably mixing tantalum pentoxide and molybdenum disilicide according to a weight proportion that the tantalum pentoxide is 1% to 7% and molybdenum disilicide is 93% to 99%; dispersing by ultrasonic wave and ball milling and mixing to obtain a dry powder, sintering the dry powder in a vacuum heat pressing sintering furnace at a temperature of 1400 DEG C to obtain the antalum pentoxide modified molybdenum disilicide-based composite material. The invention has the advantages that: the Ta2O5 doped MoSi2 composite material has high specific strength, high temperature resistant performance and corrosion resistance performance, strong anti-high temperature oxidation performance and anti-heat shock ability, and good conductivity for electricity and heat.

The invention discloses an aluminum and molybdenum high-temperature-resistant nodular cast iron containing chromium and copper elements. According to the technical scheme, the aluminum and molybdenumhigh-temperature-resistant nodular cast iron containing the chromium and copper elements is characterized in that the cast iron comprises, by weight, 1.4-3.6% of C, 1.5-5.2% of Si, 2.0-9.0% of Al, 0.3-3.0% of Mo, 0.5-2.5% of Cr, 0.3-1.5% of Cu, no more than 0.06% of impurity element Mg, no more than 0.06% of impurity element S, no more than 0.15% of impurity element P, no more than 0.7% of impurity element Mn, and the balance Fe. The aluminum and molybdenum high-temperature-resistant nodular cast iron containing the chromium and copper elements can resist the working temperature of 900 DEG C,has good heat shock performance, good high-temperature oxidation resistance performance and good formability, and is low in cost.

The invention discloses a high-wear-resistance high-thermal-conductivity zinc alloy containing strontium and sodium. The alloy comprises, by weight, 0.8-1.2wt% of Na, 0.2-0.3wt% of Sr, 4. 5-6.3wt% ofIn, 0.8-1.2wt% of Zr, 0.4-0. 8wt% of Si, 2.4-3.6wt% of Sn, 0.2-0.5wt% of Yb, 0.1-0.2wt% of Nd, 0.8-1.0wt% of S and the balance of zinc. Compared with a traditional zinc alloy, the high-wear-resistancehigh-thermal-conductivity zinc alloy containing strontium and sodium has excellent mechanical property and heat conduction performance.

The invention discloses a platinum alloy containing Sc and used as a high-conductivity and high-heat-conduction electrical contact material. In terms of weight percentage, the chemical composition of the alloy is: Sc:1.5‑2.0wt.%, Y:1.5‑2.0wt.%, Mo:0.8‑1.2wt.%, Sn:0.2‑0.6wt.%, Si:1.2‑ 2.6wt.%, Pd: 0.5‑1.0wt.%, Ho: 0.2‑0.6wt.%, Pr: 0.2‑0.5wt.%, B: 0.2‑0.5wt.%, and the balance is platinum. Compared with traditional electrical contact platinum alloys, this material has excellent mechanical properties, thermal conductivity and electrical conductivity.

The invention discloses a refractory medium-entropy alloy and a preparation method thereof, the refractory medium-entropy alloy is composed of three metal elements, the chemical formula is recorded as AaBbCc, and the atomic percentage content of the elements satisfies the following conditions: 15% < = a < = 70%, 15% < = b < = 70%, 15% < = c < = 70%, and a + b + c = 100. The preparation method comprises the following steps: weighing metal raw materials of each element, and carrying out electric arc melting in a non-self-consumption vacuum environment; and cooling to room temperature and taking out. Through an alloy design strategy of reducing components, the effect of stabilizing a crystal structure of'mixed enthalpy 'in a high-temperature environment can be fully played, room-temperature strengthening and toughening of the alloy can be further promoted by utilizing'mixed enthalpy', and on the premise of ensuring that the alloy has good high-temperature tissue structure stability and excellent high-temperature strength, the alloy has excellent mechanical properties and mechanical properties. And the room-temperature mechanical property of the alloy is greatly improved. A series of refractory medium-entropy alloys are prepared by using a non-consumable vacuum arc melting furnace, and the alloying degree is lower.

The invention discloses a method for preparing Cr2O3 coated aluminum borate whisker reinforced aluminum matrix composites, which relates to a method for preparing whisker reinforced aluminum matrix composites. The method overcomes the defects of poor mechanical properties and failure of use in high-temperature environment existing in the prior aluminum borate whisker reinforced aluminum matrix composites. The method comprises the steps of: 1, preparation of Cr2O3 sol; 2, preparation of Cr2O3 gel coated aluminum borate whiskers; 3, preparation of Cr2O3 coated aluminum borate whisker performed unit; and 4, preparation of the Cr2O3 coated aluminum borate whisker reinforced aluminum matrix composites by adopting a squeeze casting process. The method can be used for the whisker reinforced aluminum matrix composites.

The invention provides a Nb-Hf-Zr-TiO2 alloy bar which is prepared from the following raw materials in percentage by mass: 2-8% of Hf, 3-7% of Zr, 4-10% of TiO2 and the balance of Nb. The invention further provides a preparation method of such alloy bar. The preparation method comprises the following steps: 1, putting Nb, Hf, Zr and TiO2 into a ball mill, and uniformly mixing the raw materials by ball milling under the protection of an argon atmosphere, so as to obtain mixed powder; 2, carrying out compression molding to obtain a blank; 3, putting the blank into a shell, vacuumizing, and then enclosing the shell; 4, carrying out hot isostatic pressing to obtain a Nb-Hf-Zr-TiO2 alloy sintered body; and 5, carrying out hot extrusion to obtain the Nb-Hf-Zr-TiO2 alloy bar. The Nb-Hf-Zr-TiO2 alloy bar provided by the invention is good in room-temperature plasticity and tensile strength, is excellent in fatigue strength and high-temperature strength, and can be applied to an engine component of an aircraft turbine engine.

The invention provides a degradable biomedical forging-state magnesium alloy, and belongs to the field of degradable biomedical materials. The degradable biomedical forging-state magnesium alloy is prepared from the components in percentage by mass: 3.3 to 9 percent of Zn, 0.1 to 0.6 percent of Zr, 0.75 to 2 percent of Y, and the balance Mg, wherein the mass ratio of Zn/Y is larger than 4.38 and smaller than 6. The magnesium alloy not only has a favorable magnesium alloy and good corrosion resistance, but also has favorable biocompatibility, is suitable to be used as bone repair materials suchas a porous magnesium alloy material, a plastic surgery department material, an oral cavity oral cavity implant material and a bone lamella nail, and is particularly suitable to be used as a cardiovascular stent material and a bone repair material.

The invention relates to an engine assembly, in particular to an engine cylinder cover. The engine cylinder cover solves the preparation problem of a high-performance large engine cylinder cover. The engine cylinder cover is prepared from cast alloy comprising, by percentage content, 3.7-3.8% of carbon (C), 2.3-2.4% of silicon (Si), 0.5-0.55% of manganese (Mn), 1-3% of copper (Cu), 1-2% of stannum (Sn), 0.03-0.15% of cerium (Ce), 0.04-0.30% of yttrium (Y), 0.01-0.03% of erbium (Er), 0.15-0.25% of titanium (Ti), 0.25-0.50% of stibium (Sb), 0.15-0.25% of bismuth (Bi) and 0.12-0.20% of niobium (Nb). The dissolving rate of austenite is increased due to various rare earth elements in cast iron, so that ferrite nucleation is hindered, and the rare earth elements are strong pearlite promotion elements. The shape of graphite in the cast iron can be changed, the casting technology is improved, and normal-temperature mechanical performance and high-temperature mechanical performance of the cast iron are greatly improved.