Publication Date: 2015-Apr-08
The IP.com Prior Art Database
The proposed invention faces the challenge of measurements of round samples. It will measure the force of immersion and withdrawing of a sample into and out from the liquid by the Wilhelmy method. This method is very popular for judging wetting parameters of organic fibers e.g. used as a reinforcement in polymer composites (“Wetting behavior and surface properties of technical bamboo fibers” Colloids and Surfaces A: Physicochemical Eng. Aspects 380 (2011) 89–99). Although using this technics for metal fibers as a verification method for subsequent operation seems to be the original proposal. The concept was implemented by carried out immersion tests of single strands and bundles on tensiometer K100 (by KRUSS).
Background of the invention
Metal parts are connectable by using ultrasonic welding. During processing, the parts stay in solid state without melting. This advantage is used in wire harness production connecting round Aluminum cable to flat rectangular Copper terminals. To get reliable connection quality the surface properties of wire and terminal has to be known.
Especially roughness and cleanliness of the parts are important properties to get high connection quality. To examine these properties some technics are known that are applicable on samples. But there are also some drawbacks to consider.
To use microscopy or spectroscopy is a very time-consuming and expensive way to examine the samples surface, especially in case of round sample like wire strands. There is a commonly accepted route of roughness inspection by profilometer, but cleanliness of samples is much harder to estimate.
An acceptable indicator of surface properties seems to be how a sample is wetted by a strictly defined liquid. In case the sample has a flat surface the sessile drop method (ink test) is common approved. But it is a challenge to make similar estimations in case of a cable bundle having a construction of twisted, tens or hundreds, of single metal strands.
Another important task is to provide a method for surface inspection that simulates a total reaction of the lateral sample surface as happening in a real welding process. This didn’t work with the sessile method. In general there is awareness that surface quality of the conductor is very important for welding process (particularly ultrasonic welding) and also for specifying supplier requirements. But until now there was no easy, cheap and quick technic to measure the surface quality.
Description of the invention
The proposed invention faces the challenge of measurements of round samples. It will measure the force of immersion and withdrawing of a sample into and out from the liquid by the Wilhelmy method. This method is very popular for judging wetting parameters of organic fibers e.g. used as a reinforcement in polymer composites (“Wetting behavior and...