|Constance Fligg Elam Tipper|
16 February 1894|
New Barnet, Hertfordshire
14 December 1995 (aged 101)|
|Education||Newnham College, Cambridge|
Born the daughter of a surgeon in New Barnet, Hertfordshire, she was educated at Saint Felix School, Southwold and Newnham College, Cambridge (1912). In 1915 she joined the Metallurgical Department of the National Physical Laboratory in Teddington, but moved in 1916 to the Royal School of Mines in Kensington, west London, where in 1917 she was appointed Research Assistant to Sir Harold Carpenter. It was subsequently arranged that she should work at the Cavendish Laboratory, Cambridge. 
In 1928 she married George Tipper, a graduate of Clare College, Cambridge, and the Superintendent of the Geological Survey in India. When she left the Royal School of Mines in 1929 she settled in Cambridge and continued her work there for over 30 years.
Constance Tipper specialized in the investigation of metal strength and its effect on engineering problems. During World War II she investigated the causes of brittle fracture in Liberty Ships. These ships were built in the US between 1941 and 1945, and were the first all-welded pre-fabricated cargo ships.
Tipper established that the fractures were not caused by welding, but were due to the properties of the steel itself. She demonstrated that there is a critical temperature below which the fracture mode in steel changes from ductile to brittle. Because ships in the North Atlantic were subjected to low temperatures, they were susceptible to brittle failure. While these fatigue cracks would not propagate beyond the edges of riveted steel plates, they were able to spread across the welded joints in the Liberty ships. She developed what is now known as the "Tipper Test" to help ensure that the metal used in ship construction was sufficiently sound.
She was the first person to use a scanning electron microscope (SEM) to examine metallic fracture faces. She used a scanning electron microscope built by Charles Oatley and his team, the second SEM ever built.
- "The Production of Single Crystals of Aluminium and their Tensile Properties" (with H. C. H. Carpenter). Proceedings of the Royal Society of London (1921).
- Deformation of Metal Crystals (1935).
- The Brittle Fracture Story (1962).
- Charles, Jim and Gerry Smith. "Constance Tipper: her life and work", Materials World (1996).
- Hayes, Evelyn. "Dr. Constance Tipper: testing her mettle in a materials world", Advanced Materials & Processes (1998).
- Hetzel, Phyllis. Obituary, The Independent (1995). Retrieved on 27 May 2007.
- Cambridge Biographical Sketch. Retrieved on 27 May 2007.
- Constance Tipper: A Public Radio Commentary. Retrieved on 27 May 2007.
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