Metal-Matrix Composites and Thermal Spray Coatings for Earth Moving Machines

Liu, Li ; Weaver, Trent ; Zok, F.W. ; Levi, C.G. ; Kiser, Matthew T.

Caterpillar Inc.

关键词: Steels;    Casting;    Testing;    Processing;    36 Materials Science;   

DOI  :  10.2172/814907
RP-ID  :  NONE
RP-ID  :  FC26-01NT41054
RP-ID  :  814907

美国|英语

来源: UNT Digital Library

【 摘 要 】

In the fifth quarter, tooling for the steel MMC effort was redesigned based on the findings from the pressure casting trials of the previous quarter. While awaiting the arrival of that tooling, gravity casting trials were performed to assess modified performing technology and new hard particle systems. Steel-boride composite systems demonstrated good wetting and infiltration behavior, and fully infiltrated steel-boride composites were obtained under certain conditions. However, preform floating and particle dissolution are challenges which must be overcome. Ceramic oxide composites successfully pressure cast in a hot isostatic press at UC Santa Barbara were characterized and subject to fracture toughness testing. Resulting differences in fracture toughness are believed to be due to differences in matrix hardness, potentially imparted through reaction of the molten steel with the particles. Some evidence of bonding between the steel and oxide particles was noted on fracture surfaces. Arc lamp processing trials at Oak Ridge National Laboratory demonstrated that thermal spray coatings were successfully designed to facilitate fusion. All coatings investigated developed some degree of metallurgical bond after lamp fusion and for most coatings lamp fusion also further increased coating hardness. An overview of the progress during the 1st quarter of this project is given below. Research details are provided in the limited rights appendix to this report.