阅读说明：本技术 一种锆合金格架激光增材制造方法 (Zirconium alloy framework laser additive manufacturing method ) 是由 郝若彤 刘文涛 李宗书 王虹 赵瑞瑞 隋政 杜江平 董秋实 于 2020-12-31 设计创作，主要内容包括：本发明属于核燃料元件制造技术领域,具体涉及一种锆合金格架激光增材制造方法。建立格架的三维模型,对格架的镂空部分设计支撑结构,进行切片剖分,进行锆合金格架的激光增材制造；对制得的格架进行热处理。锆合金格架激光增材制造的参数范围：激光功率200W～250W、激光扫描速度1000mm/s～1100mm/s、激光扫描间距0.08～0.12mm,锆合金粉末铺粉厚度为0.03～0.05mm。支撑结构的激光成型工艺参数为：激光功率为100W、激光扫描间距为0.11mm、激光扫描速度为1300mm/s。制备出了符合技术指标要求的锆合金格架,解决了格架研发周期长、制造困难的问题。(The invention belongs to the technical field of nuclear fuel element manufacturing, and particularly relates to a zirconium alloy grid laser additive manufacturing method. Establishing a three-dimensional model of the framework, designing a support structure for the hollow part of the framework, slicing and subdividing, and performing laser material increase manufacturing on the zirconium alloy framework; and carrying out heat treatment on the manufactured grillwork. The parameter range of the zirconium alloy grid frame laser additive manufacturing is as follows: the laser power is 200W-250W, the laser scanning speed is 1000 mm/s-1100 mm/s, the laser scanning interval is 0.08-0.12 mm, and the powder spreading thickness of the zirconium alloy powder is 0.03-0.05 mm. The laser forming technological parameters of the supporting structure are as follows: the laser power was 100W, the laser scanning pitch was 0.11mm, and the laser scanning speed was 1300 mm/s. The zirconium alloy grillwork meeting the technical index requirements is prepared, and the problems of long development cycle and difficult manufacturing of the grillwork are solved.)

1. A zirconium alloy grillwork laser additive manufacturing method is characterized in that: establishing a three-dimensional model of the framework, designing a support structure for the hollow part of the framework, slicing and subdividing, and performing laser material increase manufacturing on the zirconium alloy framework; and carrying out heat treatment on the manufactured grillwork.

2. The zirconium alloy lattice laser additive manufacturing method according to claim 1, wherein: the parameter range of the zirconium alloy grid frame laser additive manufacturing is as follows: the laser power is 200W-250W, the laser scanning speed is 1000 mm/s-1100 mm/s, the laser scanning interval is 0.08-0.12 mm, and the powder spreading thickness of the zirconium alloy powder is 0.03-0.05 mm.

3. The zirconium alloy lattice laser additive manufacturing method according to claim 1, wherein: the laser forming technological parameters of the supporting structure are as follows: the laser power was 100W, the laser scanning pitch was 0.11mm, and the laser scanning speed was 1300 mm/s.

4. The zirconium alloy lattice laser additive manufacturing method according to claim 1, wherein: the subdivision thickness is consistent with the powder laying thickness of the zirconium alloy powder.

5. The zirconium alloy lattice laser additive manufacturing method according to claim 1, wherein: the heat treatment specifically comprises the following steps: keeping the temperature at 520 ℃ for 60min, and then cooling along with the furnace.

Technical Field

The invention belongs to the technical field of nuclear fuel element manufacturing, and particularly relates to a zirconium alloy grid laser additive manufacturing method.

Background

The spacer grid is an important component of the fuel assembly, and is used as the only component in the fuel assembly, which is in contact with the fuel rod, and the structure of the spacer grid not only needs to ensure the positioning of the fuel rod in the reactor core and the structural integrity of the fuel assembly, but also has the functions of improving the thermal performance of the fuel assembly and the like. However, the spacer grid has a complex structure and high requirements on the manufacturing process, if a conventional manufacturing means is used, the grid can be manufactured only by a plurality of complex processes such as stamping, cutting, welding and the like, and the integrated spacer grid meeting the performance requirements can be quickly and precisely manufactured by adopting a laser additive manufacturing technology.

Disclosure of Invention

The invention aims to provide a zirconium alloy grid laser additive manufacturing method, which develops exploration research on a process for preparing a full zirconium alloy grid by using a laser additive manufacturing technology, solves the problems of long research and development period and high difficulty in manufacturing and developing the grid of a fuel assembly, confirms the feasibility of the application of the additive manufacturing technology in the aspect of grid manufacturing, and realizes the application of the laser additive manufacturing technology in the field of research and development of nuclear fuel elements.

In order to achieve the purpose, the technical scheme adopted by the invention is as follows:

a zirconium alloy framework laser additive manufacturing method comprises the steps of establishing a three-dimensional model of the framework, designing a support structure for a hollow part of the framework, slicing and subdividing, and performing laser additive manufacturing on the zirconium alloy framework; and carrying out heat treatment on the manufactured grillwork.

The parameter range of the zirconium alloy grid frame laser additive manufacturing is as follows: the laser power is 200W-250W, the laser scanning speed is 1000 mm/s-1100 mm/s, the laser scanning interval is 0.08-0.12 mm, and the powder spreading thickness of the zirconium alloy powder is 0.03-0.05 mm.

The laser forming technological parameters of the supporting structure are as follows: the laser power was 100W, the laser scanning pitch was 0.11mm, and the laser scanning speed was 1300 mm/s.

The subdivision thickness is consistent with the powder laying thickness of the zirconium alloy powder.

The heat treatment specifically comprises the following steps: keeping the temperature at 520 ℃ for 60min, and then cooling along with the furnace.

The beneficial effects obtained by the invention are as follows:

the zirconium alloy grid is prepared by using the laser additive manufacturing technology, the process parameters of the laser additive manufacturing of the zirconium alloy grid are determined, the heat treatment process for eliminating residual stress and improving the mechanical property of the zirconium alloy grid is established, the zirconium alloy grid meeting the technical index requirements is finally prepared, and the problems of long development period and difficulty in manufacturing of the grid are solved.

Detailed Description

The present invention will be described in detail with reference to specific examples.

The laser additive manufacturing method of the zirconium alloy grillwork comprises the following steps:

1) the additive manufacturing process research of the zirconium alloy powder is carried out through an orthogonal test, and the parameter range of the additive manufacturing of the zirconium alloy powder is refined: the laser power is 200W-250W, the laser scanning speed is 1000 mm/s-1100 mm/s, the laser scanning interval is 0.08-0.12 mm, and the powder spreading thickness of the zirconium alloy powder is 0.03-0.05 mm.

2) The method is characterized in that three-dimensional modeling software is used for building a three-dimensional model of the framework, the framework is provided with a plurality of hollow structures, and when the length of a suspended part is greater than 2mm, zirconium alloy powder cannot support the framework, so that the framework is prone to forming failure, a supporting structure is designed for the framework, and laser forming technological parameters of the supporting structure are as follows: the laser power was 100W, the laser scanning pitch was 0.11mm, and the laser scanning speed was 1300 mm/s.

3) And (3) carrying out slicing and subdivision after adding a support structure into the model, wherein the subdivision thickness is consistent with the powder laying thickness of the zirconium alloy powder, and finally carrying out laser additive manufacturing on the zirconium alloy grillwork by using the additive manufacturing process parameters of the zirconium alloy powder determined in the step (2).

4) As the framework after laser forming has larger stress and influences the mechanical property of the framework, the framework prepared in the step 3 is subjected to heat treatment process research, and the annealing heat treatment process scheme of furnace cooling after the temperature of 520 ℃ is kept for 60min is determined.

The specific embodiment is as follows:

1) the molding process test shows that the optimal grid laser additive molding process parameters are as follows: the laser scanning speed is 1050mm/s, the scanning distance is 0.10mm, the laser power is 230W, and the powder spreading thickness is 0.04 mm;

2) determining the parameters of the laser additive forming process of the support part by analyzing the influence rule of each parameter on the laser forming framework as follows: the laser power is 100W, the laser scanning interval is 0.11mm, and the laser scanning speed is 1300 mm/s;

3) the preparation of the grillwork can be realized through a laser additive molding technology, and the process comprises the working procedures of three-dimensional solid modeling, support establishment, subdivision treatment and laser molding;

4) and (3) carrying out annealing heat treatment of furnace cooling after the grillwork is subjected to heat preservation at 520 ℃ for 60min after the laser additive forming, eliminating internal stress, improving the grillwork performance and facilitating subsequent linear cutting.

5) Finally, the zirconium alloy grillwork with the wall thickness of 0.6mm is prepared.

The Zr-4 alloy is used as a raw material to carry out laser additive manufacturing, the process parameters of powder laying thickness, laser power, laser scanning speed, scanning distance, powder laying thickness and the like are determined, the zirconium alloy grillwork is prepared, and the laser additive manufacturing process of the zirconium alloy grillwork is established.