| 摘要 |
<p>Two matching pieces of a piston are welded together by friction. Spec. one of the pieces is a tubular body forged, heat-treated or cast in aluminium or magnesium alloy. The body has an annular recess in the sidewall next the crown, into which a ring of wear-resistant metal is friction-welded. There is an upper annular band, between the piston ring support and the crown, friction-welded to the body and to the support, or may be one piece with the latter.</p> |
