Apparatus for high-throughput screw caster of multi-component gradient metal material

Patent metadata

Field	Value
Publication number	US-10913110-B2
Application number	US-201816169570-A
Country	US
Kind code	B2
Filing date	Oct 24, 2018
Priority date	Apr 26, 2016
Publication date	Feb 9, 2021
Grant date	Feb 9, 2021

Abstract

An apparatus for a high-throughput screw caster of a multi-component gradient metal material from elongate materials, such as multi-component alloy pipes, rods, profiles, and other such materials, has in the lengthwise direction a continuous gradient distribution of chemical components. The apparatus includes an online powder flow-rate regulation system, a rotary feed system, a heating system, a heat insulation system, a motor drive system, a blank forming system and a control system.

First claim

What is claimed is:

1. An apparatus for a screw caster of a multi-component gradient metal material, comprising an online powder flow-rate regulation system, a rotary feed system, a heating system, a heat insulation system, a motor drive system, a blank forming system and a control system;
wherein the online powder flow-rate regulation system comprises at least two metal powder storages, dynamic flow-rate control valves and an intermediate storage; and is configured to control feed rates of the at least two metal powders into the intermediate storage so as to control ratios of the at least two metal powders in a mixed metal powder in the intermediate storage,
wherein the at least two metal powder storages are connected with feeding holes of the intermediate storage through feeding pipelines, and the dynamic flow-rate control valves are disposed on the feeding pipelines; the online powder flow-rate regulation system is further configured to control completion of continuous feeding of the mixed metal powder from the intermediate storage into the rotary feed system through the feeding pipelines in sequence;
the rotary feed system comprises a cylindrical barrel and a screw rod; a feeding hole is disposed in an upper end of a side wall of the cylindrical barrel and connected with the feeding pipelines through a pipeline, and the screw rod is disposed inside the cylindrical barrel; an outer diameter of the screw rod is equal to an inner diameter of the cylindrical barrel, such that the mixed metal powder is fed in sequence within a gap of the screw rod after entering the barrel so that it is not further mixed and homogenized in the cylindrical barrel after being molten under a heating condition; a conical discharging hole is disposed in a bottom of the cylindrical barrel;
the heating system is configured to melt the mixed metal powder entered into the cylindrical barrel; a heating apparatus is disposed on a side wall of the cylindrical barrel;
the heat insulation system is a heat insulation jacket disposed on an outer side wall of an induction heater;
the motor drive system comprises a drive motor, a drive shaft and a drive shaft connector,
wherein the drive motor is in drive connection with the screw rod through the drive shaft and the drive shaft connector; and a joint between the drive shaft connector and the cylindrical barrel is sealed by a sealing ring;
the blank forming system comprises a mold, condensation crystallizers and a drawing apparatus;
the mold is disposed at a lower end of a conical discharging hole, the condensation crystallizers are disposed at two sides of the conical discharging hole inside the mold, and the drawing apparatus is disposed at a lower end of the conical discharging hole of the mold;
the powders are sequentially molten according to a feeding order within the cylindrical barrel and then flow into the conical discharging hole along a helical gap of the screw rod, so that a multi-component gradient metal material is fabricated in a draw-casting manner under a common action of the mold, the condensation crystallizers and the drawing apparatus; and
the control system comprises an upper computer and a control signal processor; and the upper computer is in control connection with the drive motor, the dynamic flow rate control valves and the induction heater through the control signal processor.

2. The apparatus according to claim 1 , wherein a ratio of an inner diameter D B of the cylindrical barrel to a root diameter D 0 of the screw rod is 1.5-8:1; an outer diameter of the screw rod is equal to an inner diameter of the cylindrical barrel, and there is no gap between the screw rod and the cylindrical barrel, such that a feeding movement of the mixed metal powder, components of which continuously change, and a flowing procedure of the mixed metal powder after being molten within the barrel are ordered and controllable, and the powders with different components and a melt are mixed and homogenized.

3. The apparatus according to claim 1 , wherein an axial distance between two consecutive flights of the screw rod is B; and B=D B tan Φ, wherein D B represents the inner diameter of the barrel, and Φ represents a helix angle of 30° to 60° of the screw rod.

4. A method for using the apparatus according to claim 1 , comprising the following steps:
step 1, respectively adding corresponding metal powders into powder storages ( 1 ) according to the number of alloy components and a variation gradient of the components, controlling dynamic flow-rate control valves ( 2 ) by an upper computer ( 11 ) to obtain contents of the metal powders required every time, sequentially making the metal powders enter into an intermediate storage ( 3 ) for being uniformly stirred and mixed to obtain a mixed metal powder in the intermediate storage, components of which continuously change, and feeding the mixed metal powder into a barrel ( 13 ) through feeding pipelines and a feeding hole ( 8 ), and meanwhile, driving a screw rod by the upper computer ( 11 ) through a drive motor ( 4 ) to rotate at a rotation speed r;
step 2, after entering into the barrel ( 13 ) and flowing the mixed metal powder driven by the screw rod ( 14 ), wherein there is no gap between a spiral blade of the screw rod ( 14 ) and the inner wall of the barrel ( 13 ), such that a movement procedure of the mixed metal powder, components of which continuously change, is ordered and controllable, and the components are not further mixed and homogenized in the barrel; and
step 3, controlling a heating system ( 15 ) by the upper computer ( 11 ) to heat the barrel at a certain power to melt the mixed metal powder, components of which continuously change, according to a feeding order under an action of the heating system ( 15 ), and making a molten metal powder flow in sequence along a gap formed between the screw rod and the inner wall of the barrel, and enter into a mold ( 17 ) through a discharging hole ( 12 ) in the bottom of the barrel ( 13 ), solidifying the molten metal powder under a condensation action of condensation crystallizers ( 18 ) and finally fabricate a metal blank ( 20 ) components of which continuously change under the action of a drawing apparatus ( 19 ), so that a fabrication of a multi-component gradient metal material is achieved.

5. The method according to claim 4 , wherein a rotation speed r of the screw rod in the step 1 is calculated by the following formula:
r =( veDe 2 cos Φ)/{( D B 2 −D S 2 )· B},

wherein r represents the rotation speed of the screw rod; Φ represents a helix angle of the screw rod; D S represents a diameter of the screw rod; D B represents an inner diameter of the cylindrical barrel; D e represents a diameter of the feeding hole; v e represents a feeding speed and a discharging speed; and B represents an axial distance between two consecutive flights.

6. The method according to claim 4 , wherein the heating power P in the step 3 is calculated by the following formula:
P≥{rBCρV ( T m −T 0 )}/( L·η ),
wherein P represents the heating power; r represents a rotation speed of the screw rod; B represents an axial distance between two consecutive flights; C represents a specific heat capacity of the material; ρ represents a density of a fabricated gradient material; V represents a unit transport volume of the material; T m represents a melting point of the material; T 0 represents an initial temperature of the material; L represents a length of the cylindrical barrel itself; and η represents a heat absorption efficiency of a material being heated.

Assignees

• Univ Beijing Science & Technology

Inventors

• Li Jingyuan
• Qi Mingfan
• Chen Yulai
• Hong Huiping
• Xie Jianxin

Classifications

• B22D11/114

  by using agitating or vibrating means (B22D11/117 takes precedence) · CPC title

• B22D11/10

  Supplying or treating molten metal (B22D41/00 takes precedence) · CPC title

• B22F2207/01

  Composition gradients · CPC title

• B29C67/00

  Shaping techniques not covered by groups B29C39/00 - B29C65/00, B29C70/00 or B29C73/00 · CPC title

• B33Y30/00

  Apparatus for additive manufacturing; Details thereof or accessories therefor · CPC title