Method for preparing fiber-reinforced metal matrix composites by multi-channel needle-free friction stir processing

Abstract

The invention discloses a large-diameter multi-pass pin-less friction stir processing method for fabricating fiber-reinforced metal matrix composites. Firstly, metal matrix sheets are ground and cleaned in advance; secondly, a preprocessed fiber net or unidirectional fiber bundle is clamped between the two metal matrix sheets in a prearranging manner, and needs to be completely covered and sufficiently protected by the covering sheets; meanwhile, a pin-less friction stir tool is slightly inclined and mounted; the pin-less stool is started to rotate to rub the surface of the covering sheet and move, a plastic deformation gradient field generated by the forging and torsional effects of the shoulder is utilized, consequently, not only can the oxide skin of the metal matrix interface be broken, but also the metal matrix which heats to be softened can plastically flow around the fibers to wrap the fibers, and thereby the fiber / matrix and the matrix / matrix interfaces can be compactly combined. A pin-less stir head with a large diameter more than 40mm to 50mm is adopted to carry out multi-pass multi-layer friction stir processing, and thereby a large, thick fiber-reinforced metal matrix composite plate can be produced. The addition of brazing filler metal can solve the contradiction between fiber injury and interface bonding improvement.

Description

Technical field: [0001] The invention belongs to the field of welding, and relates to a method for preparing metal-matrix composite materials by stirring friction, in particular to a method for preparing fiber-reinforced metal-matrix composite materials by multi-channel needle-free friction-stir processing. Background technique: [0002] The remarkable advantage of continuous fiber-reinforced metal matrix composites is that the strengthening effect is extremely significant, far exceeding the performance of the metal matrix. This is because the load in continuous fiber-reinforced metal matrix composites is mainly borne by high-strength fibers, and the main role of the matrix is Adhesive and fixed reinforcement; good plasticity to transmit and distribute load; protect matrix from environmental damage -38, 80-84.]. The metal matrix usually exists continuously and densely surrounds any reinforcement, while the fibers are distributed in the matrix in an independent network or un...

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Problems solved by technology

[0008] For traditional solid-phase diffusion and hot-pressing preparation methods, the furnace heating method commonly used has the disadvantages of slow heating, long construction period, need for protection or vacuum environment, high energy consumption, small size of furnace and workpiece, complex and expensive pressurization equipment, and interface film removal. and poor interface phase controllability, etc., the purpose of the present invention is to develop a simple, energy-saving, low manufacturing cost and low equipment investment, high flexibility fiber reinforced metal matrix composite technology

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