A laboratory investigation of mineralisation of organic materials by metal corrosion products

• Main Authors: Meng-ken Lee, 李孟懇
• Other Authors: Gordon Turner-Walker
• Format: Others
• Language: en_US
• Published: 2010
• Online Access: http://ndltd.ncl.edu.tw/handle/66868581954578901524

碩士 === 雲林科技大學 === 文化資產維護系碩士班 === 98 === Humans are good at using any natural materials. According to different characteristics of materials, humans choosing to make composite artefacts is quite common. Metal materials with special surface finish, suitable processing characteristics. Metal materials when combined with ivory, bone, leather and feather, can be made into a variety of decorativeobjects. However, organic and inorganic material have different degradationa, and objects that are made of these materials, the degradation results are absolutely different. Metal is easily affected in the atmosphere to produce metal corrosion products which can contaminate other objects, but corrosion products can sometimes protect organic materials against bacterial or biological attack. This research can be explain degradation causes by simulating organic materials in contact with metals in a sodium chloride solution. In an artificial degradation situation, determining pH value, weight change and microscopic images, we may understand how these factors work and investigate various degradation mechanisms. The results show that sodium chloride solution affected the deterioration degree of the specimens quite obviously, especially the iron specimens. The pH values are the result of organic hydrolysis and electrochemistry of metals. In the weight changes, ivory and bone with the silver and copper specimens, the weight reduced. Other specimens except leather, only have weight increased a little bit. Microscope images show the structure of the horn sheet is susceptible to corrosion and affects a weight change, and internal structural changes. Leather has significant changes in appearance cause by infiltration degree. Feathers and hair preservation depends on the situation of metal coated with corrosion products. This result can provide some information to conservators and archaeologist that face these composite materials.