METHOD FOR PRODUCING B4C/AL NEUTRON-ABSORBING MATERIAL SHEET BY CONTINUOUS CAST ROLLING

• US 20160332219A1
• Filed: 07/27/2016
• Published: 11/17/2016
• Est. Priority Date: 01/28/2014
• Status: Abandoned Application

• Current Assignee: China Nuclear Power Engineering Company Limited (CGN Power Co., Ltd.), China General Nuclear Power Group, Tsinghua University
• Original Assignee: China Nuclear Power Engineering Company Limited (CGN Power Co., Ltd.), China General Nuclear Power Group, Tsinghua University
• Inventors: Shu, Guogang, Li, Qiulin, Luo, Zhiyuan, Liu, Yanzhang, Zhang, Tengfei, Liu, Wei, Wang, Xin, Li, Xuejun
• Application Number:
  US15/220,440
• Publication Number:
  US 20160332219A1
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: B22D 11/003 Aluminium alloys
• CPC Class Codes: B22D 11/0622 formed by two casting wheels
• CPC Class Codes: B22D 11/0642 Nozzles nozzles used in open-ended moulds B22D41/50
• CPC Class Codes: B22D 11/114 by using agitating or vibrating means B22D11/117 takes precedence
• CPC Class Codes: B22D 11/115 by using magnetic fields
• CPC Class Codes: B22D 11/122 using magnetic fields
• CPC Class Codes: B22D 21/007 with low melting point, e.g. Al 659 degrees C, Mg 650 degrees C
• CPC Class Codes: B22F 2202/01 Use of vibrations
• CPC Class Codes: B22F 2202/05 Use of magnetic field
• CPC Class Codes: C22C 1/1036 starting from a melt
• CPC Class Codes: C22C 21/00 Alloys based on aluminium
• CPC Class Codes: C22C 32/0057 based on B4C
• CPC Class Codes: G21F 1/08 Metals; Alloys; Cermets, i.e. sintered mixtures of ceramics and metals

Abstract

The present invention provides a method for producing B4C/Al neutron-absorbing material sheet by continuous cast rolling including the steps of: 1) providing B4C particles and aluminum matrix melt, adding the B4C particles into the aluminum matrix melt while stirring the composite of the B4C particles and the aluminum matrix melt; 2) applying an electromagnetic field to the B4C particle-containing aluminum matrix melt passing through a headbox; 3) applying an ultrasonic vibration to the B4C particle-containing aluminum matrix melt passing through a casting nozzle; and 4) conducing twin roll continuous cast rolling on the B4C particle-containing aluminum matrix melt from the casting nozzle to obtain B4C/Al neutron-absorbing material sheet. The method of the present invention uses twin roll continuous cast rolling under coupled ultrasonic and electromagnetic oscillation to rapidly cool and refine the grains of the solidified composite material and realize uniform distribution of B4C particles in the aluminum matrix.

Claims

1. A method for producing B4C/Al neutron-absorbing material sheet by continuous cast rolling, comprising the steps of:

1) providing B4C particles and aluminum matrix melt, adding the B4C particles into the aluminum matrix melt while stirring the composite of the B4C particles and the aluminum matrix melt;

2) applying an electromagnetic field to the B4C particle-containing aluminum matrix melt passing through a headbox;

3) applying an ultrasonic vibration to the B4C particle-containing aluminum matrix melt passing through a casting nozzle; and

4) conducing twin roll continuous cast rolling on the B4C particle-containing aluminum matrix melt from the casting nozzle to obtain B4C/Al neutron-absorbing material sheet.

2. The method of claim 1, wherein a particle size of the B4C particles is 0-44 μ

m.

3. The method of claim 1, wherein in step 1), the aluminum matrix melt comprises ≦

0.25 wt % Si, ≦

0.35% wt Fe, ≦

0.05 wt % Cu, ≦

0.03 wt % Mn, ≦

0.03 wt % Mg, ≦

0.10 wt % Zn, ≦

0.10 wt % Ti and ≧

99.60 wt % Al.

4. The method of claim 1, wherein in step 1), prior to being added into the aluminum matrix melt, the B4C particles are preheated in an air atmosphere at 300°

C.-500°

C. for 2 h-2.5 h and fully dried in a vacuum drying oven.

5. The method of claim 1, wherein in step 1), the aluminum matrix melt is obtained via melting the aluminum matrix under 5-10 Pa vacuum and setting the aluminum matrix melt at 720°

C.-730°

C. for 15-20 minutes while applying mechanical stirring to the aluminum matrix melt.

6. The method of claim 5, wherein in step 1), the aluminum matrix melt is subjected to standing, refining and slagging-off.

7. The method of claim 1, wherein in step 1), the stirring is carried out at a temperature of 690-720°

C., a stirring speed of 600-800 rpm, and a stirring time of 15-30 min.

8. The method of claim 1, wherein in step 2), the electromagnetic field generates an electromagnetic oscillation via interaction of a constant magnetic field and a low frequency alternating magnetic field to achieve electromagnetic dispersion.

9. The method of claim 8, wherein in step 2), the constant magnetic field adopts a direct current of 180 A-200 A, a coil turns of 80-120, a magnetic field direction of coil axis, and a magnetic field intensity of 0.1-0.4 T;

the low frequency alternating magnetic field adopts an alternating current of 80 A-100 A, a coil turns of 80-120, an alternating current frequency of 20 Hz-40 Hz, a magnetic field direction of coil axis, an effective magnetic field strength of 0.05-0.3 T, and an oscillation time of 1.5-2 min.

10. The method of claim 1, wherein in step 3), the ultrasonic vibration is applied from top side, a power of the ultrasonic vibration is 240 W-300 W, and a vibration time of the ultrasonic vibration is 150-180 s.

11. The method of claim 1, wherein in step 4), the twin roll continuous cast rolling uses copper twin rollers, a loading between the twin rollers is 25-30 KN, a rotation speed of the twin rollers is 0.9-1.2 m/min, and the twin rollers are cooled by water.

12. The method of claim 1, wherein a mass content of the B4C particles in the B4C/Al neutron-absorbing material sheet is 20-31%.

13. A B4C/Al neutron-absorbing material sheet produced by the method of claim 1.