74results about How to "Reduce macro segregation" patented technology

The invention relates to a method for the vertical semi-continuous direct chill casting of composite billets or plates comprising at least two layers of aluminum alloys, using a separator which is in contact with the solidification front and which provides a seal between the two alloys during casting, said separator being vibrated while it is in contact with the solidification front, so that the separator is not frozen in and entrained by the solid metal. The invention also relates to a device that can be used to carry out said method.

A method and equipment for vertical semi-continuous casting of light alloy large-size ingots with synergistic effects of power ultrasound and low-frequency electromagnetics, which adopts vertical semi-continuous casting of light alloy large-size ingots that can be applied with the synergy of two external fields, power ultrasound and low-frequency electromagnetics Equipment, apply low-frequency electromagnetic field and power ultrasonic field or low-frequency electromagnetic oscillation field and power ultrasonic field at the same time during the casting process, the power ultrasonic field acts on the axis of the crystallizer, and the electromagnetic field acts near the surface of the metal melt, through the adjustment of the two external field parameters Realize the synergistic effect, so that the whole volume of the external field can be cast during the solidification process of the crystallizer melt; The size effect of ingot casting defects, greatly improving the internal and surface quality of vertical semi-continuous casting light alloy large ingots.

The magnesium alloy electromagnetic low-temp. semicontinuous casting method includes the steps of melting magnesium, adding compound fire-resisting elements, adding alloy elements, heat-insulating, standing still and semicontinuous casting under the electromagnetic field. It utilizes the addition of compound fire-resisting elements to implement smelting of magnesium alloy free from coverage or protection so as to shorten technological process and raise melt quality, and utilizes the application of electromagnetic field and optimization of crystallizer structure to implement the low-temp. and high-speed semicontinuous casting of magnesium alloy.

The invention discloses a Cu-Fe composite double-melt mixed casting equipment and process, comprising a first melting furnace for heating and melting pure Cu; a second melting furnace for heating and melting Cu-Fe alloy; a mixing chamber, The flow guide tube communicates with the liquid outlets of the first melting furnace and the second melting furnace to mix the heated and melted pure Cu and Cu-Fe alloy; The body is heated and electromagnetically stirred; the crystallizer is docked with the liquid outlet of the mixing chamber; the stopper mechanism is used to control the opening and closing of the liquid outlet and the melt flow of the first melting furnace and the second melting furnace; An air pressure regulating mechanism for adjusting the air pressure in the first melting furnace and the second melting furnace. The casting equipment and process not only solve the problem of inhomogeneous composition and structure of Cu-Fe composite materials in the casting process, but also can significantly improve production efficiency and reduce production costs, and are suitable for industrial scale production.

The invention discloses a method and device for homogenizing a large ingot solidification structure by combining a static magnetic field with a rotating magnetic field. Through the electromagnetic oscillation effect generated by a combined magnetic field and the rotational flow induction stirring effect of the rotating magnetic field, nucleation is promoted, dendritic crystal tips are crushed, crystal grains are refined, the solidification structure is homogenized, macroscopic segregation is reduced, and therefore the method and the device are used for the large ingot casting process. When metal melt is solidified, the static magnetic field and the rotating magnetic field are exerted to a heat preservation riser in a combined mode according to the characteristics that metal liquid at an ingot mould riser is solidified lastly, the riser wall and the metal liquid surface are easy to nucleate first, and the rotating magnetic field and the static magnetic field can easily permeate a riser material, the metal liquid in the heat preservation riser is effectively oscillated and stirred, and the metal liquid in the riser is delivered into the metal liquid at the center of an ingot mould through oscillating and rotational flow stirring; the dendritic crystal tips are crushed, the crystal grains are refined, the solidification structure is homogenized, macroscopic segregation is reduced, a compact, homogenized and crystal grain-refined large ingot is obtained, and therefore the subsequent machining performance and service performance of the large ingot are improved.

The invention relates to a homogenized copper-nickel-tin alloy rod and a preparation method thereof. The formula is as follows in terms of mass percentage: Zn is 0.01%-0.026%, Sn is 7.9%-8.2%, Nb is 0.02%-0.05%, Ni+Co is 14.0%‑16.0%, Fe is 0.01%‑0.02%, Mg is 0.01%‑0.15%, the rest is Cu, and Co accounts for 0%‑5.0% of the total mass of Ni+Co. The preparation method includes batching, smelting, homogenization treatment, forging, aging treatment and grinding steps. The hardness of the bar of the present invention is HRC≥35, and the tensile strength σ b ≥998Mpa, yield strength σ 0.2 ≥950Mpa, elongation δ≥6%, good uniformity of chemical composition of the bar, short production process and low manufacturing cost.