Forged Aluminum Sputtering Targets With Uniform Grain and Texture
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Solution Overview
Problem
Current aluminum and aluminum alloy sputtering targets face challenges such as cast defects, non-uniform grain sizes, and texture banding due to mechanical rolling processes, which can lead to inconsistent sputtering properties.
Innovation Solution
A method involving frictionless forging followed by rolling and heat treatment is employed to produce sputtering targets with uniform grain sizes and textures, using graphite as a lubricant to reduce friction and achieve homogeneous deformation, resulting in a microstructure with minimal texture banding and consistent grain size distribution.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If standard casting followed by significant rolling is used to process aluminum sputtering targets, then manufacturing complexity is reduced, but the grain size uniformity and texture homogeneity deteriorate due to cast defects and texture banding
Solution Approach 1:
The patent applies frictionless forging by changing the processing parameter from conventional rolling to frictionless forging, which fundamentally alters the deformation mechanism. This parameter change eliminates the texture banding and grain size non-uniformity issues inherent in rolling processes while maintaining manufacturing feasibility
Solution Approach 2:
The patent introduces graphite as a friction-reducing intermediary between the billet and press plates during forging. This intermediary enables frictionless forging conditions, allowing uniform deformation throughout the billet without the defects associated with conventional rolling, thereby achieving both ease of manufacture and high precision
2Loss of time
If conventional rolling is used to reduce billet height, then processing time is reduced, but texture banding and non-uniform deformation occur
Solution Approach 1:
The patent changes the fundamental processing parameter from rolling to frictionless forging, which achieves rapid height reduction similar to rolling but with uniform deformation throughout the material. This parameter change eliminates texture banding while maintaining efficient processing time
Solution Approach 2:
Graphite sheets are introduced as a friction-reducing intermediary that enables the forging process to proceed rapidly without creating the non-uniform deformation and texture banding associated with conventional rolling, thus achieving both speed and uniformity
3Manufacturing precision
If frictionless forging is used to achieve uniform deformation, then grain size uniformity is improved, but process complexity increases
Solution Approach 1:
The patent uses graphite sheets as a simple, easily implementable intermediary that enables frictionless forging. This approach achieves uniform grain size and eliminates texture banding without requiring complex equipment modifications, as graphite is a readily available and easy-to-apply friction reducer
Solution Approach 2:
The patent implements frictionless forging by changing the friction parameter at the interface between billet and press plates. This parameter change achieves superior grain uniformity through a relatively simple process modification rather than requiring complex manufacturing systems
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 effectively eliminates defects like feather grains and texture banding, producing sputtering targets with uniform grain sizes and textures, enhancing their sputtering properties and manufacturing consistency.
Implementation Method 1
placing a sheet of graphite at an interface between an aluminum or aluminum alloy billet and press plates of a forging press; forging the aluminum or aluminum alloy billet to at least a 50% reduction in height with the forging press
Implementation Method 2
heat treating the reduced aluminum or aluminum alloy billet at a temperature of 250°C -300°C for 1 to 2 hours to form a sputtering target characterized as having an average grain size between 15 μm and 55 μm and characterized by a microstructure having a random texture
Implementation Method 3
heat treating the reduced aluminum or aluminum alloy billet at a temperature of 250°C -300°C for 1 to 2 hours to form a sputtering target characterized as having an average grain size between 15 μm and 55 μm and characterized by a microstructure having a random texture
Data Source
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AI summary
A sputtering target comprising a forged aluminum material having an average grain size between about 15 and 55 microns. The aluminum material has at least one of the following: a homogeneous texture with minimal texture banding as measured by banding factor B below about 0.01; a texture gradient H of less than 0.2; or either weak (200) texture or near random texture characterized by maximum intensity of inverse pole figure less than 3 times random in multiple directions.