Development of NZP ceramic based {open_quotes}cast-in-place{close_quotes} diesel engine port liners

Technical Report · Thu Feb 01 04:00:00 EST 1996

DOI:https://doi.org/10.2172/374437· OSTI ID:374437

Nagaswaran, R; Limaye, S Y

BSX (Ba{sub 1+x}Zr{sub 4}P{sub 6-2x}Si{sub 2x}O{sub 24}) and CSX (Ca{sub l-x}Sr{sub x}Zr{sub 4}P{sub 6}O{sub 24}) type NZP ceramics were fabricated and characterized for: (i) thermal properties viz., thermal conductivity, thermal expansion, thermal stability and thermal shock resistance; (ii) mechanical properties viz., flexure strength and elastic modulus; and (iii) microstructures. Results of these tests and analysis indicated that the BS-25 (x=0.25 in BSX) and CS-50 (x=0.50 in CSX) ceramics had the most desirable properties for casting metal with ceramic in place. Finite element analysis (FEA) of metal casting (with ceramic in place) was conducted to analyze thermomechanical stresses generated and determine material property requirements. Actual metal casting trials were also conducted to verify the results of finite element analysis. In initial trials, the ceramic cracked because of the large thermal expansion mismatch (hoop) stresses (predicted by FEA also). A process for introduction of a compliant layer between the metal and ceramic to alleviate such destructive stresses was developed. The compliant layer was successful in preventing cracking of either the ceramic or the metal. In addition to these achievements, pressure slip casting and gel-casting processes for fabrication of NZP components; and acoustic emission and ultrasonics-based NDE techniques for detection of microcracks and internal flaws, respectively, were successfully developed.

• Research Organization: Oak Ridge National Lab., TN (United States); LoTEC, Inc., West Valley City, UT (United States)
• Sponsoring Organization: USDOE, Washington, DC (United States)
• DOE Contract Number: AC05-96OR22464
• OSTI ID: 374437
• Report Number(s): ORNL/Sub--92-SL922/1; ON: DE96015149
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
BARIUM OXIDES
CALCIUM OXIDES
CERAMICS
LINERS
MECHANICAL PROPERTIES
PHOSPHORUS OXIDES
PHYSICAL PROPERTIES
SILICON OXIDES
SLIP CASTING
STABILITY
STRESSES
TEMPERATURE DEPENDENCE
THERMAL CONDUCTIVITY
THERMAL EXPANSION
THERMAL SHOCK
ZIRCONIUM OXIDES