A Study of Frictional Adhesion between Dissimilar Metals with a Background of Development of Cold Pressure Welding Using Interfacial Slide

研究了滑动摩擦作用下异种金属间的粘附特性，为界面滑动冷压焊接提供了理论依据。根据研究课题，首次进行了销板式滑动摩擦试验。铝具有很强的附着力，但出现了铁、镍、钛等材料根本没有附着力的问题。这个问题和一个额外的困难，即没有提供关于滑动长度的影响的信息，这是实际连接过程中的重要因素之一，让我们停止使用摩擦试验。然后用盘对盘滑动黏附试验代替销对板滑动黏附试验。在滑动粘接试验中，一对试件在界面处通过粘接相互连接，将连接的强度作为粘接强度来测量，以便从实用的角度定量地估计粘接的程度。考察了压力和滑动长度的影响，然后评估了各种组合（包括类似金属组合）的粘附性。得到以下提示信息：1。粘接强度与滑动长度密切相关，并在一定滑动长度处达到最大值。随着压力的增大，最大滑动长度逐渐变短。2. 在相同压力下，退火材料比加工硬化材料具有更高的粘接强度。但考虑到流动应力，两者在行为上是统一的。3. 在冷压镦粗焊接中，粘接强度与开始连接的高度降低阈值呈正相关。4. 粘接强度很好地表达了粘接的程度，可以作为判断特定金属组合是否适合采用界面滑动进行冷连接工艺的指标。

Characteristics of adhesion between dissimilar metals under sliding friction were investigated to serve for cold pressure welding using interfacial slide. Pin-on-plate type sliding friction test was at first applied according to the research project. Aluminum showed strong adhesion, but a problem arose that iron, nickel and titanium chosen as the materials did not show adhesion at all. The problem and an additional difficulty that no information was presented on the effect of sliding length, one of important factors in actual joining processes, let us to stop using the friction test. Then a disc-on-disc type sliding adhesion test was employed in place of the pin-on-plate type test. In the sliding adhesion test, a pair of test- pieces joined each other at the interface by adhesion, and the strength of joining was measured as adhesive strength in order to estimate the degree of adhesiveness quantitatively from practical view point. Influences of the pressure and sliding length were examined, and after that adhesiveness in the various combinations including similar metal ones were evaluated. And the following suggestive information was obtained:1. Adhesive strength strongly depends on sliding length and shows a maximum at a certain sliding length. And the maximum shifts to shorter sliding length with an increase of the pressure. 2. An annealed material shows higher adhesive strength than work-hardened one in the same pressure. But taking flow stress into consideration, both are unified on behavior. 3. Adhesive strength shows a correlation with the threshold of reduction in height to start joining in cold pressure welding by upsetting. 4. Adhesive strength well expresses the degree of adhesiveness, and it can be used as the index to judge whether a particular metal combination is suited to apply cold joining process using interfacial slide.