Plasma Spray Joiningof Al-Matrix Particulate Reinforced Composites
T. ITSUKAICHI, T. W. EAGAR, M. UMEMOTO, I. OKANE
WELDING JOURNAL
Abstract
Aluminum matrix composite joints have been produced on both alu- minum alloy and metal matrix compos- ite (MMC) substrates using powders con- taining Sic and A1203particulates. Most of the composite powders were pro- duced by ball milling, but the most ef- fective joints were produced using Os- prey composite powders. The results of preliminary joining experiments indicate that the substrateshould be preheated to 200 and a very wide bevel angle should be provided in order to obtain the highest strength joints. Silicon alloy ad- ditions to the matrix significantly im- proved strength but titanium additions had no effect. Heat treatment after spray- ing significantly improved the bond strength and restored precipitation hard- ening in the matrix. Significant amounts of Mg were lost from the deposit during sprayingwhile some free silicon was pro- duced by pyrolysis of the SiC powder; hence, further efforts must develop pow- der compositions that produce the opti- mum matrix composition in the sprayed deposit. Hot isostatic pressingof the sam- ples to eliminate porosity had only a small effect on the final strength of the joints. No significant amount of A14C3 was detected in deposits which con- tained Sic.
keywords:Plasma spray; Particulate composites; SiC particulates; Preheating; Ball-milled powders; AI-Matrix Composites; Spray Deposit Powder; AI-Si-Ti Powders; 2014 Al Powders; Hot Isostatic Pressure
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