Titanium engine valve and method of making

Patent · Tue Jun 30 00:00:00 EDT 1987

OSTI ID:6297508

Allison, J E

This patent describes a method of making a dual microstructure titanium based engine valve. A first zone of the valve contains essentially a mixture of fine, equiaxed alpha and transformed beta crystalline grains which exhibit high tensile strength and high fatigue resistance. A second zone contains essentially colony type alpha/beta crystalline grains exhibiting resistance to high temperature creep, the method comprising: (a) preparing valve stock for each of the zones of forgeable mixed phase alpha/beta titanium based material; (b) hot working the first zone at a temperature below the beta transus temperature; (c) forging the second zone and, either simultaneously with or subsequent thereto, heat treating the second zone at a temperature above the beta transus temperature for a period of time to achieve beta processing followed by cooling of the second zone to a temperature of 1400/sup 0/F at a rate of 0.1-10.0/sup 0/F/second; and (d) heat treating, immediately subsequent to step (b) or step (c) at least the first zone at a temperature below the beta transus temperature for a period of time to achieve alpha/beta processing.

• Assignee: Ford Motor Co., Dearborn, MI
• Patent Number(s): US 4675964
• OSTI ID: 6297508
• Country of Publication: United States
• Language: English

Related Subjects

33 ADVANCED PROPULSION SYSTEMS
330603* -- Vehicle Design Factors-- Engine System
CONTROL EQUIPMENT
COOLING
CREEP
CRYSTAL STRUCTURE
ELEMENTS
ENGINES
EQUIPMENT
FABRICATION
FLOW REGULATORS
FORGING
HEAT TREATMENTS
HOT WORKING
MATERIALS WORKING
MECHANICAL PROPERTIES
METALS
MICROSTRUCTURE
TEMPERATURE EFFECTS
TENSILE PROPERTIES
TIME DEPENDENCE
TITANIUM
TRANSITION ELEMENTS
VALVES
VEHICLES
VERY HIGH TEMPERATURE