Heat-Resistant Casting Dendrite Orientation for Turbocharger Caulking

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Solution Overview

Problem

Existing heat resistant castings for turbochargers face challenges with poor plastic deformation characteristics, leading to undesired deformation or cracking during caulking processes, which require large plastic deformation.

Innovation Solution

A heat resistant casting with an axial portion containing dendrites structured to have an average angle between the direction perpendicular to the central axis and the main axes of the dendrites within a range of 20 degrees, enhancing the plastic deformation characteristic and enabling improved joining strength through caulking.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If heat resistant casting is installed by plastic processing such as caulking, then the body characteristic is less affected, but the heat resistant casting has poor plastic deformation characteristic and does not deform uniformly, causing undesired deformation or a crack

Engineering Contradiction:
Improvebody characteristic stabilityVSAvoidplastic deformation characteristic
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The invention applies local quality by creating a specific dendrite structure configuration in the axial portion of the heat resistant casting. The dendrites are oriented at a controlled angle (10-30 degrees) relative to the axial direction, creating a localized structural characteristic in the axial portion that differs from the rest of the casting. This local structural modification enables uniform plastic deformation during caulking while maintaining the overall heat resistant properties of the casting.

Inventive Principle:
Principle #3Local quality

2Strength

If heat resistant casting is incorporated into the body by welding, then the joining is achieved, but the body may cause distortion due to local heating or cooling, or the heat resistant casting or the body may be affected by heat

Engineering Contradiction:
Improvejoining strengthVSAvoidbody distortion
Core Design Contradiction:
StrengthVSManufacturing precision

Solution Approach 1:

The invention replaces the thermal joining method (welding) with a mechanical joining method (plastic deformation through caulking). By controlling the dendrite structure in the axial portion, the material becomes suitable for plastic deformation, allowing the axial portion to be joined to the body through caulking instead of welding. This substitution eliminates the harmful thermal effects of welding while achieving strong mechanical joining.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

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 heat resistant casting effectively prevents undesired deformation or cracking during caulking, achieving uniform deformation and increased joining strength, making it suitable for high-temperature applications like turbocharger nozzle vanes.

Implementation Method 1

dendrites in a structure of a region of an axial portion that is subjected to plastic processing, the dendrites having an average angle between a direction perpendicular to a central axis of the axial portion and main axes of the dendrites in a range of 20 degrees

Methodology Applied
Scientific EffectDendritic crystal structure: Crystallisation

Implementation Method 2

the heat resistant casting of the embodiment has a larger deformation in the region having an excellent plastic processing characteristic, compared to a conventional heat resistant casting, when processing such as caulking that accompanies a large plastic deformation

Methodology Applied
Scientific EffectPlastic deformation: Plasticity

Data Source

PatentEP3321390B1Heat-resistant casting
Publication Date: 2024.02.14 MITSUBISHI STEEL MFG CO LTD
  • EP3321390B1 patent drawingFigure 1
  • EP3321390B1 patent drawingFigure 2A~2B
  • EP3321390B1 patent drawingFigure 3A~3B

AI summary

A heat resistant casting having an axial portion includes dendrites in a structure of a region of the axial portion subjected to plastic processing. The dendrites have an average angle between a direction perpendicular to a central axis of the axial portion and main axes of the dendrites in a range of 20 degrees.