Abstracts

Dr. Diran Apelian

Phases in Metallic Alloys and Use of Phase Diagrams

Phases in materials engineering will be defined and explained in this lecture, and the use of phase diagrams will be reviewed. Phase transformations will be discussed, and in particular invariant transformations such as eutectic and peritectic reactions will be reviewed in detail. Concepts of solubility limits, phase separation, intermetallics will be discussed and illustrated with the use of phase diagrams. Modern software tools that aid in navigating through complex alloy systems and determining the phases that precipitate out during solidification will also be reviewed, and case studies will be presented.

Dr. Francesca G. Bewer

A brief history of the restoration and conservation of metal objects.

The talk aims to provide a brief overview of the history of metal restoration and conservation, and hopes to

illustrate the shifting notions of the behavior of materials - and of different categories of art -- and their impact on contemporary restoration practices, and
provide representative examples of objects that have undergone identifiable or documented treatments.

The talk will focus on objects made out of bronze, but will include some information on the treatment of works made of other metals and alloys as well.

Studying the the Art of the Bronze Founder in Western European Culture.

The seminar aims to :

provide an overview of the bronze casting methods used in the past to produce sculptures
examine in what ways an understanding of the materials and techniques is beneficial for the connoisseurship and conservation of bronze sculpture, and
show what kinds of evidence technical sleuths rely on to reconstruct how ancient and historical bronzes were produced.

Our presentation will draw from case studies from our own research on ancient and Renaissance bronzes. It will consist mainly of slide presentations, but we hope to make up for this when the group comes to the Straus Center for Conservation, where we will offer a short hands-on study session of metal sculptures from the Harvard University Art Museums' collections.

Dr. Ron Biederman

Forensics Research with Metal Objects: WTC Steel Case Study

Several steel samples from Buildings 7, 1 and 2 of the World Trade Center were collected during the Federal Emergency Management Agency forensic investigation shortly after the September 11, 2001 incident. Macroscopically the steel samples supplied exhibited severe “erosion” with plate thickness varying from 12.7mm to a total loss of metal in many areas. Also, some localized plastic deformation was observed. A determination of the cause of this unexpected erosion and an estimate of the maximum temperature that this steel likely experienced are the subjects of this investigation.

Jeffrey Forgeng

Conservation at the Higgins Armory Museum

This session will offer a close-up and hands-on look at representative cases in metals conservation as faced by the Higgins Armory. Focus will be on current conservation projects, chiefly for the museum’s upcoming exhibition on arms and armor in Shakespeare.

Metals and the Martial Imagination

Since the advent of bronze over 5,000 years ago, metals have conferred enormous military advantages for those who could effectively produce, craft and deploy them. In part due to their practical usefulness, in part due to their esthetic possibilities, metals also acquired powerful symbolic power: even a relatively ordinary metal like iron enjoyed a measure of mystique. This presentation will examine the imaginative history of metals in martial contexts from the golden helmets of Mesopotamia to the intricate military devices of Leonardo da Vinci, with a walk-through of the Higgins collections that will highlight the relationship between metals and the martial imagination.

Martha Goodway

Recent Alloys

Most of the metal elements in use today have a long history; iron and copper are examples. Other metal elements were introduced later, some quite recently. The major difference between modern and traditional metals has been in the development of a multiplicity of alloys. Some are well known; stainless steel is an example. Most recent alloys have not been so successful. Some of these alloys were never recorded and can present serious problems of identification, not to mention treatment.

Dr. Jianyu Huan

Electron Microscopy and Its Application in Metals

An introduction of principle of Transmission Electron Microscopy (TEM),which includes topics such as what is a TEM, the major components in a TEM, the image formation mechanism, bright field image, dark field image, high resolution image, electron diffraction pattern, and energy dispersive x-ray spectroscopy (EDS) is presented first. This is followed by a brief introduction to crystals, dislocations in crystals, the role of TEM in the study of dislocations, and how this has advanced the history metallurgy. Finally some examples of using TEM to study the dislocation structures in severely deformed copper are described. The possible role of TEM in the preservation of historic metals will be mentioned.

Edward A. Hunter

Introduction to Metals Conservation: Illustrated through the Conservation of Arms and Armor

This talk will provide an introduction to the conservation of metals, with the focus on the conservation of arms and armor in the Metropolitan Museum of Art, where the Armor Shop has been exclusively devoted to the care of the collection since 1906. In that time the skills, knowledge and techniques of metals conservation have developed and changed. In the earliest days when skilled armorers were hired as restorers it was not uncommon to fabricate new armor elements or to re-forge damaged ones. By the end of the twentieth century, the adoption of a modern conservation philosophy guided the care of the arms and armor down a different path. This philosophy places an emphasis on minimum intervention and preserving the history and appearance of an object, rather than extensive restoration.

Issues of good conservation practice, such as reversibility or minimum intervention, must be balanced with the need for practicality. Much of the armor in the MMA collection would be undisplayable without restorations done in the early days of the Museum, and the armor was handled with care and sensitivity for its original elements. Today, though restoration is far less common, some of the lessons of our predecessors are still useful.

The conservation of arms and armor requires sensitivity to many aspects of the material and its artistic possibilities. Even minimal treatment can affect the surface appearance of the metal. The conservator’s job is to understand the material and to conserve and care for the art in a way that highlights the aesthetic qualities of the metal, while mitigating deterioration and past damage.

Ralph E. Napolitano

The Origin of Metals

The mere mention of extractive metallurgy conjures up the dramatic images of immense caldrons of fire and molten metal that were indelibly etched into the American culture during the industrial revolution of the 20th century. During this period, steel and its related products became a foundation upon which cities were raised, forging a brotherhood among those whose blood and sweat built the world’s first true industrial empire. Their efforts were rewarded through the explosion of innovation, invention, and production that ultimately swept the globe, enabling far-reaching advancements in transportation, communications, energy production, architecture, and agriculture. This powerful legacy, however, is only a brief chapter in the longstanding and ongoing relationship between mankind and metal. Beginning with the working of native metals and the fortuitous discovery of metal smelting, the knowledge and skill of the metallurgist has been essential in the development of civilization. Even today, the development of new alloys which are stronger, lighter, stiffer, and more durable, continues to provide the means for technological advancement into the 21st century.

In this session, we briefly explore the origin of metals and metallic alloys from both scientific and historical perspectives. Topics include:

Early smelting and extraction processes: "Fire, brimstone, and some luck"
The availability of metals: "Big Blue Marble" or "The Planet Metallica"
Basic principles of extractive metallurgy
Contemporary extraction processes
The production of Fe, Cu, Ni, Al, Pb, Sn: "Truly precious metals"
Current challenges

Both historical and contemporary methods of metal extraction and processing are discussed and detailed examples of specific alloys and applications are given.

Brian Newbury

Emerging Non-Destructive Analysis Methods in Archaeometallurgy: Synchrotron Based X-ray Techniques and Optical Profilometry

In this seminar the problem of non-destructively determining bulk metallurgical data from archaeological and historical metal samples shall be discussed. The synchrotron is a large machine which generates coherent high energy X-rays (10-100 keV) for a wide range of experiments. A group of 40 Islamic and European astrolabes dating from the 13th to 19th century was studied by this completely non-destructive technique. By impinging a high energy (70-80 keV) beam of x-rays capable of transmitting through the brass astrolabes (up to 1cm thick); metallurgical data can be produced from the bulk of the samples without any harm to them. X-ray diffraction, fluorescence, and radiography experiments were performed on the astrolabes and will be discussed. Emphasis will be placed on exactly what one can learn about the forming history, composition, and metallurgy of an archaeological/historical metal sample. Diffraction experiments allowed the composition of the bulk samples as well as mechanical deformation and forming histories to be determined. X-ray fluorescence experiments allowed the near surface (~20 mm) compositions to be determined, while radiography allowed mapping of the relative thickness. From these experiments and the forming history, it is possible to obtain information about microstructural characteristics and compositions of the astrolabes that no other non-destructive technique could furnish. These data were used to learn more about technical and metalworking techniques used by the astrolabe manufacturers, as well as to determine if any astrolabe parts were later (or modern) replacements. Optical profilometry analysis of surface engraving techniques will also be illustrated, allowing one to study surface markings of a sample in quantitative detail. In addition, historical brass-making technology in the European and Islamic world and brass conservation issues shall be discussed.

Michael Notis

Fabrication, Metallography, and Conservation of the Japanese Sword

This presentation will cover the history, and fabrication processing, of the Japanese sword, starting from smelting of iron by the Tatara process, to forging of the sword component segments, quench hardening, and final polishing. The fabrication context, in terms of cultural and accompanying religious ceremony, will be discussed. The development and changes in sword shape and structure over time, from early history to the medieval period, will be highlighted. Microstructures of swords from selected specimens will be examined in detail and related to fabrication processing.

Because iron is susceptible to rapid corrosion attack, it is often important to understand and interpret the corroded structural remains of iron objects in order to reconstruct and identify the original microstructure, and hence to comprehend the original fabrication processing of iron artifacts. Various examples of remnant microstructures will be shown in order to demonstrate the interaction between corrosion conditions and the complex microstructures in representative iron objects. This will enable a better understanding of proper methods for conservation of such objects.

Malcolm Parkinson

How useful was theoretical mechanics in explaining the properties of materials before the Industrial Revolution?

Concentrating on the period from about 1600 to 1750, this lecture examines whether theoretical mechanics was useful to craftsmen in explaining the properties and behavior of materials. Through examining the works of major figures such as Galileo and Newton during the "Scientific Revolution," this study shows how difficult it was to apply the new science of mechanics to materials, both ferrous and non-ferrous.

Matthias Pfaffenbichler

Surface Treatments of Decorated Iron Surfaces

The talk will discuss the different decoration technologies like etching, gilding, hammering, polishing , painting and enamel and the problems which arouse when corrosion damages the surface. The talk will discuss the problem of restauration from an aesthetic aspect as well as from the aspect of conservation.

The Conservation of Ferrous Metals

The talk will discuss the conditions which make corrosion of ferrous metals possible. The measures which should be taken to prevent corrosion or to stabilise already corroded iron objets . The problem of restaurations and its long term results.The promblems which arouse with the conservation of objects made out of different materials. Ferrous metals and leather, ferrous metals and wood. The aesthetic aspects of the conservation of ferrous metals.

Dr. Aldo M. Reti

Precious Metals Metallurgy and Related Topics

Basic metallurgical aspects of Gold, Silver, Platinum and their alloys will be discussed with the aid of simple phase diagrams, which are useful tools to understand structure/properties relationships; the Karat System for gold will be reviewed, as well as quantitative color descriptions (yellow, red, green and white golds) using the international CIELAB system. Special processing techniques employed for centuries to produce gold leaf and depletion gilding will be explained. Other common forms of gold, known as gold filled and rolled gold plate as well as their manufacturing methods will be discussed.

Sterling Silver properties and processing can be best understood from the silver-copper phase diagram. In addition, the importance of proper deoxidation practices will be pointed out. An interesting old technique to develop surface texture, known as reticulation, will be explained.

There are six elements in the periodic table that make-up the family known as Platinum Group Metals; the most common alloys will be mentioned and important considerations for melting platinum will be discussed.

The presentation will include a review of the Legal Requirements for precious metals in the U.S. and the Hallmarking laws in the U.K.

Dr. Yancy W. Riddle

Characterizing Metallic Microstructures

In this session we will discuss some basic principles of metallurgical sample preparation pertinent to both optical and electron microscopy, as well as X-ray diffraction. We will also discuss the operation of optical microscopy, scanning electron microscopy, transmission electron microscopy, and various X-ray techniques including some fundamental physics associated with them. The goal is to expose students to the research potential and types of information that can be derived from these valuable tools.

David. A. Scott

Introduction to copper alloys

The native metals. Transition from use of native copper for small tools and ornaments to smelted copper. Smelting of copper ores and production of arsenical copper and tin bronze. The nature of copper alloys of different compositional types. Working and casting of copper and copper alloys.

Introduction to the copper-tin phase diagram

Why we need metallography, what metallography can tell us about structure and properties. Discussion of different types of copper alloys, differences between low-tin and high-tin bronzes. effect of lead additions, other phase types found in quenched copper alloys and their uses and some account of the issues of patina and corrosion. Introduction to the metals practical session which will be taking place this morning.

Practical metallographic session with copper alloys already mounted for examination.

The group of 20-25 students will be divided into groups of three (or four) so that each group will work on a selected number of copper alloys materials and will report on their observations to the rest of the group.

This will involve the need for 8 metallographic microscopes, polishing equipment using Buehler mastertex cloth employing 6 micron and 1 micron diamond (polycrystalline) in aqueous suspension, ethanol wash bottles for rinsing, fine tissue lab paper for drying, specimen drier, if microscopes not inverted stage, will need glass slides and plasticine and specimen leveller device....if inverted, these not needed.....will need the following etchants made up...ammonia/hydrogen peroxide.....alcoholic ferric chloride......ammonium persulphate and lead thiosulphate complex colour etch...details in my book "Metallography and Microstructure of Ancient and Historic Metals (1991 Getty Press).......will need also dual slide projector facilities as well as the powerpoint being sent by disc.....will need demonstration metallographic microscope with video display to show class details of structure.....

Richard D. Sisson

The Physical Metallurgy of Steel

The mechanical properties and performance of steel can be manipulated by controlling the chemical composition and heat treatment process parameters. In this presentation the physical metallurgy of the processing - structure - properties relationships will be presented and discussed in terms of the kinetics of the phase transformations and the Fe – C phase diagram. Both current and historical examples will be used to illustrate the important issues.

Richard D. Sisson, Jr.

Corrosion: the Environmental Degradation of Materials

When you go out into the world to look for metallic iron or copper (or almost any metal) you do not find the metal you find the ore (i.e. dirt). The metallic form of most metals is not stable at normal atmospheric conditions. The process that transforms metals to the various oxides, hydroxides, carbonates and sulfates is called corrosion. In this presentation these electrochemical processes will be discussed with emphasis on the role of water/humidity/steam as well as the kinetics and thermodynamics of the chemical reactions. The role of various alloying elements on corrosion will also be presented and discussed. The eight forms of corrosion will be highlighted and discussed in terms of several current and historic materials systems.

Robert van Langh

Precious Metals

The field of understanding, authenticating, conserving and preserving a silver object starts with the material and it’s manufacturing technique. Many things can be learned by looking through the eyes of a silversmith or similar crafstman, yet solely the craftsman point of view has been proven insufficient many times. The basis for future accurate understanding and conserving of silver objects should include; the combination of skills from a craftsman, materials scientist, conservation scientist and specialised art historian. Authentication can only take place if the conservator in charge respects these insights and collaborates with the specialisms mentioned.

Authentication Examples will be given where it seems to be likely that any research undertaken in one specific field, only brought the presumption of dating an object instead of finding proof of it’s origin or technique. One of the emphases during this presentation is put on technological insights.

Examples of pictures with an explanation of the slides will be given where questions will be asked from the participants what they think they are looking at, how we can recognise it and how we can proove this. It should emphasize that especially metals conservation concerns any of the specialised fields and it’s interaction.

Conservation What are the current possiblities for metals conservation, where have we been focussing on, what is relevant and what not. E.g. who has ever seen that filliform corrosion was a problem with silver? A pragmatic overview of the conservation related problems and possible solutions from a practical point of view.

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Last modified: Jul 17, 2007, 11:34 EDT