45results about How to "Refine matrix tissue" patented technology

The invention discloses a liquid-state near-net forming method and device for a continuous carbon fiber enhanced aluminum-based composite material, namely a vacuum-assisted pressure-adjusting and infiltration casting method and device. The method comprises four procedures of smelting an alloy and pre-heating fibers, carrying out vacuum-assisted pressure-adjusting and infiltration, condensing at a high pressure and cooling rapidly. The device is composed of an alloy smelting device, a vacuum-assisted pressure-adjusting and infiltration device and a casting rapid cooling device. The liquid-state near-net forming method and device have the characteristics that (1) low-oxygen and temperature-controllable pre-heating of nickel-plated carbon fibers is realized; (2) low-pressure infiltration and high-pressure condensation of the aluminum-based composite material are realized; (3) the control of a cooling speed in the condensation of a composite material casting is realized. According to the liquid-state near-net forming method and device for the continuous carbon fiber enhanced aluminum-based composite material, oxidization and burning loss caused by pre-heating the carbon fibers, prefabricated body deformation in the infiltration process and interface reaction problems in the condensation process of the composite material are solved. The liquid-state near-net forming of the continuous carbon fiber enhanced aluminum-based composite material can be realized and the prepared composite material has the advantages of dense tissues, few interface reactions, high mechanical properties and the like.

The invention relates to the technical field of structure refinement and homogenization of bearing steel, in particular to high-carbon bearing steel and a preparation method thereof. The high-carbon bearing steel comprises the following chemical components: 0.80-1.20 wt% of C, 0.40-2.0 wt% of Cr, 0.15-0.75 wt% of Mn, 0.15-0.75 wt% of Si, 0-0.20 wt% of Nb, 0-0.20 wt% of Mo, 0-0.20 wt% of V, less than or equal to 0.015 wt% of P, less than or equal to 0.01 wt% of S and the balance of Fe and inevitable impurities, wherein the contents of Nb, Mo and V are not 0 at the same time. The microalloying elements Nb, Mo and V are added into the high-carbon bearing steel and are matched with other element components, so that the matrix structure of the bearing steel can be effectively refined, a large amount of nano carbide is promoted to be separated out, and the contact fatigue life of the high-carbon bearing steel is further prolonged.

The invention discloses an isothermal superplastic deformation method for a micro / nano particulate reinforced titanium matrix composite. The method comprises the following steps of A, preparing a titanium boride and rare earth oxide micro / nano particulate hybrid reinforced titanium matrix composite by utilizing an in-situ synthesis technique, and performing vacuum consumable electrode arc melting on the composite for more than two times; B, performing cogging forging on the composite in a Beta single-phase region, wherein deformation amount is greater than or equal to 50 %; performing isothermal forging on the composite in an (Alpha + Beta) two-phase region to obtain a titanium matrix composite forging blank, wherein deformation amount is greater than or equal to 60 %; and C, performing hot rolling on the titanium matrix composite forging blank in a near Beta phase region, wherein deformation amount is greater than or equal to 80 %, and performing annealing treatment to obtain the micro / nano particulate reinforced titanium matrix composite. The micro / nano particulate reinforced titanium matrix composite is formed by the isothermal forging technology and hot rolling, and thus, the matrix structure can be effectively refined, and the material forming rate is increased; and a plate has good superplasticity within the deformation process range of 800-1000 DEG C and 5 x 10<-3>-10<-4>s<-1>.

The invention discloses a production method of a steel wear-resistant plate BTW for coal mines. The production method comprises the steps of steel ingot billeting, billet heating, high-pressure water dephosphorization, rolling, cooling and straightening. The invention controls the heating curve, optimizes the design of the rolling schedule, and controls the rapid cooling after rolling to obtain the steel wear-resistant plate BTW for coal mines with good surface quality, and the strength and wear resistance meet the requirements of users, and is widely used in the field of coal mines. The BTW thickness specification of the steel wear-resistant plate for coal mine obtained in the present invention is 15-50mm, and after the use performance is agreed with the user: the guaranteed tensile strength is ≥700MPa, the yield strength is 400-480MPa, and the impact energy is ≥80J; the wear-resistant plate BTW has a flat shape, Flatness ≤ 5mm / 1m, surface quality meets the requirements of GB / T14977 Class B, steel plate delivery without grinding.

The invention relates to a method for preparing acicular second phases to improve the degradation resistance of medical magnesium alloys. The magnesium alloy includes an AZ61 matrix and acicular Al uniformly distributed in the matrix 4 Ce phase. Its preparation method is as follows: ball milling Ce powder and AZ61 powder to obtain mixed powder, and then preparing acicular Al-containing powder by SLM 4 Ce phase magnesium alloy. On the one hand, the present invention can significantly refine matrix grains and acicular Al 4 The Ce phase structure, on the other hand, increases the solid solubility of solute elements and inhibits Mg 17 Al 12 Precipitation of the second phase. Acicular Al 4 The Ce phase has both a smaller potential difference and a larger resistance to the matrix, which can inhibit galvanic corrosion; and the Al 4 The Al in the alloy is consumed during the formation of Ce, which can also reduce and refine the original Mg in the alloy 17 Al 12 Phase, thereby reducing galvanic corrosion, the two work together to improve the degradation resistance of magnesium alloys, thereby promoting its application in degradable implants.

The invention discloses a high-current and high-power maintenance-free slip ring. The high-current and high-power maintenance-free slip ring comprises a mounting plate, wherein a bearing pedestal is arranged on the top surface of the mounting plate; an inner ring of the bearing pedestal is connected with the slip ring; a stand column I is arranged on the top surface of the slip ring; the top end of the stand column I is connected with a rotating ring; the stand column I is provided with conductive rings; an outer ring of the bearing pedestal is connected with a stand column II; the top end of the stand column II is connected with a protective cover; the stand column II is provided with electric brushes with conductive columns; the conductive columns are elastically connected with the corresponding electric brushes through springs; the conductive columns are connected with the corresponding conductive rings in a fitting manner; a dust holding groove is formed in the connecting place between the stand column II and the outer ring of the bearing pedestal; and the corresponding fitting places between the conductive columns and the conductive rings are vertically corresponding to the dust holding groove. The stand column I is driven by a shifting fork to rotate so as to enable the conductive rings and the corresponding conductive columns on the electric brushes to be in friction constantly to realize electric connection; powder generated in the friction can naturally fall into the dust holding groove without being cleaned, so that the maintenance-free effect is realized; and in addition, the cost is effectively lowered while the reliability is high.

The invention relates to a smelting method of high-toughness and high-strength casting-state ductile cast iron. The smelting method comprises the steps of 1, material selection, in which pig iron, scrap steel and a melting-back material are selected as raw materials; 2, material preparation, in which 20-40% of pig iron, 30-40% of scrap steel and 20-50% of melting-back material are selected according to percent by mass; 3, smelting, in which the raw materials prepared in the step 2 are added into a medium-frequency smelting furnace, the temperature is raised, the raw materials are molten, a carburant is added to the bottom of the furnace during smelting, and the raw materials are molten to a required furnace outlet temperature; 4, nodulization and casting, in which a nodulization pack and acasting pack are pre-heated to 600-800 DEG C before nodulization, a nodulizing agent, an inoculation agent and a coverage agent are sequentially placed in the nodulization pack placement pit, and inoculation for three times is performed; and 5, box outlet. The smelting method is simple to operate; and by adding the scrap steel and the melting-back material in a large proportion, the production cost is low, and the mechanical property is improved by a reasonable proportion.