Papers by Keyword: Physical Analysis

Abstract: Printed circuit boards (PCBs) and copper-clad laminate (CCLs) are the foundation of the electronic industry, and the core components of all kinds of electronic products. With the accelerated pace of information equipment replacement, waste PCBs and CCLs increase every year, and generated a lot of e-waste. Sweden Ronnskar smelter made an analysis on elements of the PCBs used in the personal computer, the results showed that the PCBs generally contain precious metals gold, silver and non-ferrous metals such as copper, wherein the mass fraction of copper is up to 26.8%, the mass concentration of gold and silver respectively reached 80 g/t and 3300 g/t, which much higher than the average gold grade and having high recycling value. Waste PCBs also contain heavy metals such as lead, cadmium, chromium, which have a great deal of harm to the environment and human body. This paper focuses on the physical and chemical properties of the electronic circuit board such as calorific value and moisture, on the content measurement and analysis of gold, copper and other precious metals so that the physical and chemical properties of the ingredients in waste PCBs and CCLs are determined from a qualitative and quantitative point of view, which is very important for looking for recyclable value of the waste PCBs and CCLs and for determining the best method of recycling them. The test results showed that the waste PCBs and CCLs had very high recycling value.

Abstract: The operational fault of diesel engine caused by losing the required function in running is a random phenomenon. It needs to collect a large number of fault samples and reliability data to reveal the fault occurrence rule and describe it with mathematical method. In this paper, the fault law and mechanism of the engine connecting rod were researched by the physical and chemical analysis of the fault samples. The fault reasons and the fault mechanism can be found through the analysis of the organization structure, material properties, process features, heat treatment process and other reliability information of the fault sample. It can provide scientific basis for the failure exclusion as well as the optimization and improvement of connecting rod structure.