Machining of Fe[sub 3]Al intermetallics

Book · Wed Jan 01 00:00:00 EST 1992

OSTI ID:6274249

Woodyard, J R

Scientists at the US Bureau of Mines are studying iron aluminides as possible substitutes for stainless steels to reduce the Nation's dependence on imported strategic and critical materials. In a Bureau investigation on the mechanical properties of Fe-28Al, it was found that the material's machining properties were significantly improved at slow tool and feed speeds. Machining techniques normally used for brittle materials failed or were costly. Further experiments using a 5-in (12.7-cm) mill cutter with carbide inserts, operating dry at minimum machining speeds, produced visually smooth sample surfaces with no tool damage. As a result of these experiments and a review of published data on hydrogen embrittlement of iron aluminide under tension, non-water-based (e.g., sulfur-based) lubricants were chosen for production machining. Four-flute, 3/4-in(19-mm) carbide end mills were used at slow speed under lubrication. This latter procedure reduced tool wear and breakage by a factor of 2. Machined surfaces and specimen cross sections were analyzed by scanning electron microscopy to detect microcracking. Tensile tests gave the expected yield and ultimate strengths, indicating that no degradation by low-speed machining occurred. This study extends this work to show that the alloy can be machined at higher speeds using high-speed steel end mills, and that water-soluble cutting oil is a suitable lubricant and coolant. 11 figs., 1 tab.

• OSTI ID: 6274249
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATION
ALUMINIUM ALLOYS
MACHINING
BINARY ALLOY SYSTEMS
MECHANICAL PROPERTIES
IRON BASE ALLOYS
STAINLESS STEELS
MATERIAL SUBSTITUTION
HYDROGEN EMBRITTLEMENT
LUBRICANTS
SCANNING ELECTRON MICROSCOPY
TENSILE PROPERTIES
WEAR
ALLOY SYSTEMS
ALLOYS
ELECTRON MICROSCOPY
EMBRITTLEMENT
HIGH ALLOY STEELS
IRON ALLOYS
MICROSCOPY
STEELS
360101* - Metals & Alloys- Preparation & Fabrication
320302 - Energy Conservation
Consumption
& Utilization- Industrial & Agricultural Processes- Materials
360103 - Metals & Alloys- Mechanical Properties