Metal Plate Lamination Machining to Prevent Welding Defects

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing additive manufacturing techniques face challenges in forming laminated structures with desired shapes due to issues like void-like defects, material flow-out, and groove-like defects during the joining process, which affect the accuracy and efficiency of the laminated structure formation.

Innovation Solution

An additive manufacturing method and apparatus that incorporates a supply device, a joining device capable of friction stir welding, electron beam welding, laser welding, or plasma welding, and a machining device with cutting and surface-finishing functions to form laminated structures by repetitive lamination and machining of metal plates, with specific techniques to manage joining paths and machining processes to prevent defects and ensure accurate shape formation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If friction stir welding is used to join metal plates in additive manufacturing, then the joining strength and material mixing are improved, but void-like defects and groove-like defects occur due to material flow-out and improper joining path

Engineering Contradiction:
Improvejoining strengthVSAvoidshape accuracy
Core Design Contradiction:
StrengthVSManufacturing precision

Solution Approach 1:

The patent applies preliminary action by performing surface finishing machining on the metal plate before friction stir welding. This pre-machining of the joining surface prevents material flow-out and groove-like defects during welding, ensuring both strong joining and accurate shape formation without void-like defects

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent applies local quality by selectively machining only the joining surface area of the metal plate before welding, rather than the entire plate. This localized surface finishing ensures the joining area has optimal quality for welding while maintaining the overall plate integrity and preventing defects at the joining zone

Inventive Principle:
Principle #3Local quality

2Shape

If metal plates are cut to form partial shapes, then the desired laminated structure shape is achieved, but material waste increases and joining paths become complex

Engineering Contradiction:
Improvelaminated structure shapeVSAvoidmaterial waste
Core Design Contradiction:
ShapeVSLoss of substance

Solution Approach 1:

The patent applies partial action by performing surface finishing only on the joining surfaces of metal plates rather than machining the entire plate to the final shape immediately. This allows material to be retained and removed in subsequent layers, reducing overall material waste while achieving the desired complex laminated structure shape through iterative partial machining

Inventive Principle:
Principle #16Partial or excessive action

3Manufacturing precision

If multiple machining processes are performed on each metal plate, then the surface quality and shape precision are improved, but the manufacturing time and process complexity increase

Engineering Contradiction:
Improvesurface qualityVSAvoidmanufacturing efficiency
Core Design Contradiction:
Manufacturing precisionVSProductivity

Solution Approach 1:

The patent applies segmentation by dividing the machining process into distinct phases: surface finishing machining performed before welding to prepare joining surfaces, and shape machining performed after welding to form the final structure. This segmentation allows each machining operation to be optimized independently, maintaining high surface quality and shape precision while improving overall manufacturing efficiency by avoiding redundant operations

Inventive Principle:
Principle #1Segmentation

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The method and apparatus enable the formation of laminated structures with high accuracy and efficiency by preventing void-like and groove-like defects, ensuring precise shape formation and minimizing material waste, thus enhancing the practicality of additive manufacturing.

Implementation Method 1

a joining device configured to heat the metal plate and the laminate-joined body to join the metal plate and the laminate-joined body

Methodology Applied
Scientific EffectFriction stir welding: Friction Welding

Implementation Method 2

Friction stir welding (FSW) is a technique for welding plural metal plates by inserting a dedicated tool into the plate while rotating the tool at high speed to soften the material by the generated frictional heat

Methodology Applied
Scientific EffectFrictional heat: Viscous Heating

Implementation Method 3

causing the material near the location where the tool is inserted to be plastically flowed and mixed by rotational force

Methodology Applied
Scientific EffectPlastic flow: Plasticity

Data Source

PatentEP3659806B1Additive manufacturing method and additive manufacturing apparatus
Publication Date: 2023.03.15 OKUMA CORP
  • EP3659806B1 patent drawingFigure 1
  • EP3659806B1 patent drawingFigure 2A~2D
  • EP3659806B1 patent drawingFigure 3

AI summary

A supply device (2) places a metal plate (22a, 22b) on a laminate-joined body, and a joining device (3) heats the metal plate (22a, 22b) and the laminate-joined body to join the metal plate (22a, 22b) and the laminate-joined body. A machining device (4) machines the one or plural metal plates (22a, 22b) joined to the laminate-joined body to form a laminate-joined body including the one or plural metal plates (22a, 22b) laminated on the laminate-joined body. A first machining function (5) of the machining device (4) cuts the metal plate (22a, 22b) to form a partial shape of a laminated structure (32). A second machining function (6) of the machining device (4) finishes a surface of the metal plate (22a, 22b). The first machining function (5) cuts the metal plate (22a, 22b) to leave a region that lies outside and extends from the partial shape.