Effect of Casting Procedures and Diesel Engine Environment on the Behavior of Aluminum Titanate.

摘要

The purpose of this report is to document the final results and conclusions of work on the behavior of aluminum titanate materials in a diesel engine environment. The work was conducted in three phases. Phase 1 covered investigation of material properties and microstructures of aluminum titanate materials from three different manufacturers. Phase 2 consisted of testing and evaluation of the material properties and microstructure, of each of the materials, after environmental exposures. Phase 3 work involved investigation of casting procedures to produce a cast-in-place exhaust port. Temperature profiles were recorded and different external compliant layers and core sand compositions were examined. The aluminum titanate material from the three different manufacturers showed significant differences in strength, stability and thermophysical properties. One material was low density with low strength, modulus and conductivity. The second material exhibited degradation to alpha-Al2O3 after aging at temperatures greater than 1000 C. The third material had very high strength as-received but showed a strength loss of up to 40% after aging. However, the strength for this material after aging remained greater than the as-received strength of the other two materials. The casting studies showed that cast-in-place ports can be produced. The most promising results were seen when the core sand composition was 50% SiC/50% Fe. (sdw)