209 results about "Fretting wear" patented technology

A coated electrically conductive substrate has particular utility where there are multiple closely spaced leads and tin whiskers constitute a potential short circuit. This electrically conductive substrate has a plurality of leads separated by a distance capable of bridging by a tin whisker, a silver or silver-base alloy layer coating at least one surface of at least one of the plurality of leads, and a fine grain tin or tin-base alloy layer directly coating said silver layer. An alternative coated electrically conductive substrate has utility where debris from fretting wear may increase electrical resistivity. This electrically conductive substrate has a barrier layer deposited on the substrate that is effective to inhibit diffusion of the substrate into a subsequently deposited layers, which include a sacrificial layer deposited on the barrier layer that is effective to form intermetallic compounds with tin, and a low resistivity oxide metal layer deposited on the sacrificial layer.An alternative coated electrically conductive substrate has particular utility where debris from fretting wear may oxidize and increase electrical resistivity, such an in a connector assembly. This electrically conductive substrate has a barrier layer deposited on the substrate that is effective to inhibit diffusion of constituents the substrate into a plurality of subsequently deposited layers. The subsequently deposited layers include a sacrificial layer deposited on the barrier layer that is effective to form intermetallic compounds with tin, a low resistivity oxide metal layer deposited on said sacrificial layer, and an outermost layer of tin or a tin-base alloy directly deposited on the low resistivity oxide metal layer.In this alternative embodiment, the barrier layer is preferably nickel or a nickel-base alloy and the low resisitivity oxide metal layer is preferably silver or a silver-base alloy.When heated, the coated substrate of this second embodiment forms a unique structure having a copper or copper-base alloy substrate, an intervening layer formed from a mixture or metals including copper and tin, and an outermost layer which is a mixture of a copper-tin intermetallic containing phase and a silver-rich phase. It is believed that this silver-rich phase is particularly beneficial to reduce an increase in resistivity due to oxidation of fretting wear debris.

A grid strap includes a spacer grid spring that increases the conformal contact area with a fuel rod of a nuclear fuel rod assembly. The shape of the spacer grid spring of the grid strap which is in contact with the fuel rod is optimized, thereby the elasticity of the spacer grid spring contacting the fuel rod is increased, the conformal contact area with a contact portion of the spacer grid spring contacting the fuel rod when the fuel rod is inserted into each cell of a spacer grid is expanded to obtain uniform stress distribution, and excessive plastic deformation of the spacer grid spring can be reduced. Further, magnitude and distribution of contact pressure between the fuel rod and the spacer grid spring are improved, thereby reducing the possibility of fretting wear caused by contact between the fuel rod and the spacer grid spring. The elastic behavior region of the spacer grid spring is expanded, so that the fuel rod can be reliably supported until the lifetime of the fuel rod expires despite changes in the supporting conditions of the fuel rod.

A coated electrically conductive substrate has particular utility where there are multiple closely spaced leads and tin whiskers constitute a potential short circuit. Such substrates include leadframes, terminal pins and circuit traces such as on printed circuit boards and flexible circuits. This electrically conductive substrate has a plurality of leads separated by a distance capable of bridging by a tin whisker, a silver or silver-base alloy layer coating at least one surface of at least one of the plurality of leads, and a fine grain tin or tin-base alloy layer directly coating said silver layer.An alternative coated electrically conductive substrate has particular utility where debris from fretting wear may oxidize and increase electrical resistivity, such an in a connector assembly. This electrically conductive substrate has a barrier layer deposited on the substrate that is effective to inhibit diffusion of constituents the substrate into a plurality of subsequently deposited layers. The subsequently deposited layers include a sacrificial layer deposited on the barrier layer that is effective to form intermetallic compounds with tin, a low resistivity oxide metal layer deposited on said sacrificial layer, and an outermost layer of tin or a tin-base alloy directly deposited on the low resistivity oxide metal layer.In this alternative embodiment, the barrier layer is preferably nickel or a nickel-base alloy and the low resisitivity oxide metal layer is preferably silver or a silver-base alloy.When heated, the coated substrate of this second embodiment forms a unique structure having a copper or copper-base alloy substrate, an intervening layer formed from a mixture or metals including copper and tin, and an outermost layer which is a mixture of a copper-tin intermetallic containing phase and a silver-rich phase. It is believed that this silver-rich phase is particularly beneficial to reduce an increase in resistivity due to oxidation of fretting wear debris.