11-02-2013, 03:58 PM
Aluminum Cast Alloys
[attachment=50537]
INTRODUCTION
In modern manufacturing of metallic components, we must accept the premise that
design dictates performance, and that the role of the designer is pivotal. Moreover,
the designer must rely on databases and failure criteria that are robust and proven.
However, as design dictates performance, performance itself is attained through alloy
and process selection; both of which are quite interconnected and coupled with each
other. Historically, new processes have been developed, but these have always been
evaluated based on existing alloys rather than developing new alloys to take advantage
of the processing attributes to optimize this coupling of alloy and process. During the
last decade, we have witnessed the development of enabling tools that can be utilized
to optimize alloy development, bring in measures to better control our processes and
alloys, and in brief, tools that allow intelligent alloy development for specific performance
metrics and processes.
In this World Wide Report, we first review the fundamentals of Al cast alloys as a
primer, followed by a discussion of the various enabling tools available to the industry –
tools that were not available to the metal casting industry ten years ago or so. Specific
case studies are presented and discussed to manifest the power of these enabling tools
to improve and optimize alloy development.
Page 2 Aluminum Cast Alloys
Introduction
Aluminum Cast Alloys Page 3
2. INDUSTRY NEEDS
First and foremost, as an industry we must meet the needs of the design community.
This requires understanding the needs of designers, and to appreciate the boundary
conditions and constraints of their work.
Secondly, the casting industry should have the means and tools to tailor and optimize
alloys for specific performance. Alloy requirements for low cycle fatigue are different
than say for thermal management systems, etc. As pointed out above, developing
alloys for specific processes is not the norm, and it should be. We need to optimize the
performance attained from specific processes by ensuring that the alloys processed are
optimized to take advantage of the merits of the particular process.
Today, we have predictive tools that enable us to work in a much more intelligent and
effective way than in years past. The trial and error approach of alloy development is
not only ineffective but also economically unsustainable.
Cast components undergo post-processing operations, such as heat-treating, etc. In
complex alloys, the range of elemental composition may make all the difference during
heat-treating. Predictive tools mitigate if not prevent the occurrence of incidences such
as incipient melting. So it is not only during the alloy and processing stages that the
enabling tools are useful, but also during post-processing operations.
In brief, what the major transformation for the metal casting industry is the paradigm
shift from State-of-the-Art to State-of-Science.
Page 4 Aluminum Cast Alloys
Industry Needs
Aluminum Cast Alloys Page 5
In the ANSI (NADCA) numbering system, major alloying elements and certain
combinations of elements are indicated by specific number series, as follows:
The digit that follows the decimal in each alloy number indicates the product form. A
zero (0) following the decimal indicates the cast product itself (die casting, for instance).
A one (1) following the decimal indicates the chemistry limits for ingot used to make
the XXX.0 product. A two (2) following the decimal also indicates ingot used to make
that XXX.0 product, but ingot of somewhat different (usually tighter) chemistry limits
than that of XXX.1. While not always the case, XXX.1 often indicates secondary alloy
chemistry limits whereas XXX.2 would indicate primary alloy chemistry limits. For
example, a designation 380.0 could indicate a die cast product likely produced from
380.1 secondary ingot whereas 356.0 would might indicate a squeeze cast product
produced from 356.2 primary ingot. The important things to remember are that a “0”
following the decimal indicates a cast product whereas a “1” or “2” indicates the ingot
chemistry needed to make the cast product.
[attachment=50537]
INTRODUCTION
In modern manufacturing of metallic components, we must accept the premise that
design dictates performance, and that the role of the designer is pivotal. Moreover,
the designer must rely on databases and failure criteria that are robust and proven.
However, as design dictates performance, performance itself is attained through alloy
and process selection; both of which are quite interconnected and coupled with each
other. Historically, new processes have been developed, but these have always been
evaluated based on existing alloys rather than developing new alloys to take advantage
of the processing attributes to optimize this coupling of alloy and process. During the
last decade, we have witnessed the development of enabling tools that can be utilized
to optimize alloy development, bring in measures to better control our processes and
alloys, and in brief, tools that allow intelligent alloy development for specific performance
metrics and processes.
In this World Wide Report, we first review the fundamentals of Al cast alloys as a
primer, followed by a discussion of the various enabling tools available to the industry –
tools that were not available to the metal casting industry ten years ago or so. Specific
case studies are presented and discussed to manifest the power of these enabling tools
to improve and optimize alloy development.
Page 2 Aluminum Cast Alloys
Introduction
Aluminum Cast Alloys Page 3
2. INDUSTRY NEEDS
First and foremost, as an industry we must meet the needs of the design community.
This requires understanding the needs of designers, and to appreciate the boundary
conditions and constraints of their work.
Secondly, the casting industry should have the means and tools to tailor and optimize
alloys for specific performance. Alloy requirements for low cycle fatigue are different
than say for thermal management systems, etc. As pointed out above, developing
alloys for specific processes is not the norm, and it should be. We need to optimize the
performance attained from specific processes by ensuring that the alloys processed are
optimized to take advantage of the merits of the particular process.
Today, we have predictive tools that enable us to work in a much more intelligent and
effective way than in years past. The trial and error approach of alloy development is
not only ineffective but also economically unsustainable.
Cast components undergo post-processing operations, such as heat-treating, etc. In
complex alloys, the range of elemental composition may make all the difference during
heat-treating. Predictive tools mitigate if not prevent the occurrence of incidences such
as incipient melting. So it is not only during the alloy and processing stages that the
enabling tools are useful, but also during post-processing operations.
In brief, what the major transformation for the metal casting industry is the paradigm
shift from State-of-the-Art to State-of-Science.
Page 4 Aluminum Cast Alloys
Industry Needs
Aluminum Cast Alloys Page 5
In the ANSI (NADCA) numbering system, major alloying elements and certain
combinations of elements are indicated by specific number series, as follows:
The digit that follows the decimal in each alloy number indicates the product form. A
zero (0) following the decimal indicates the cast product itself (die casting, for instance).
A one (1) following the decimal indicates the chemistry limits for ingot used to make
the XXX.0 product. A two (2) following the decimal also indicates ingot used to make
that XXX.0 product, but ingot of somewhat different (usually tighter) chemistry limits
than that of XXX.1. While not always the case, XXX.1 often indicates secondary alloy
chemistry limits whereas XXX.2 would indicate primary alloy chemistry limits. For
example, a designation 380.0 could indicate a die cast product likely produced from
380.1 secondary ingot whereas 356.0 would might indicate a squeeze cast product
produced from 356.2 primary ingot. The important things to remember are that a “0”
following the decimal indicates a cast product whereas a “1” or “2” indicates the ingot
chemistry needed to make the cast product.