EVALUATION OF ARTIFICIAL NEURAL NETWORKS FOR PINEAPPLE GRADING

The objective of this study is to evaluate resonant frequency, firmness and soluble solids for pineapple classification using artificial neural networks (ANNs) as the analytical tool. A sample of 149 pineapples was classified based on their internal qualities into five classes: unripe, partially ripe, ripe, partially overripe and completely overripe. The developed ANN model successfully classified pineapples into merely three classes as unripe, ripe and completely overripe. The most effective model was obtained when both resonant frequency and soluble solids were included in the model. The classification accuracy was more than 83% for all three classes.     

Evolution of Intermetallic Compounds between Sn-0.3Ag-0.7Cu Low-silver Lead-free Solder and Cu Substrate during Thermal Aging

The growth, transformation, and lattice structure of intermetallic compounds formed between Sn–0.3Ag–0.7Cu lead-free solder and copper substrate were investigated. Dip soldering was used to initiate the reaction between the solder and substrate. An η-Cu6Sn5 intermetallic phase possessing a hexagonal lattice structure was found at the as-soldered interface. Thermal aging at a number of conditions resulted in the formation of a Cu3 Sn intermetallic phase between the Cu6Sn5 layer and the copper substrate. ε-Cu3 Sn with an orthorhombic lattice structure was found together with hexagonal Cu3 Sn. Subsequently, the activation energies of the intermetallic phases were calculated and compared to results obtained from the literature. The comparison showed that good agreement existed between the findings from this study and literature data within a similar temperature range.     

Ag、Bi、In和Sb添加对Sn-0.6Cu-0.05Ni-Ge无铅焊料性能的改变（英文）

对用于替换Sn-Pb共晶焊料的Sn-Ag-Cu(SAC)焊料来说,Sn-Cu-Ni-Ge焊料是一个巨大的挑战。本文作者研究添加Ag、Bi、In和Sb对Sn-0.6Cu-0.05Ni-Ge(SCNG)无铅焊料物理性能的影响及与铜基体的界面反应。研究SCNG-x焊料的熔化行为、显微组织、抗拉强度和润湿性。结果表明,Ag、Bi、In和Sb的引入对焊料的固相温度、液相温度和抗拉强度有微小的影响。但是,合金元素的浓度会影响焊料的冷却性能和凝固组织。除锑以外的合金元素的添加,提高了SCNG焊料的润湿性。合金元素的加入增加了金属间化合物层的厚度,这与焊料的冷却行为有关。SCNG-x焊料与铜基体之间的金属间化合物层形貌与典型的SAC焊料不同。总之,用Ag、Bi、In或Sb对SCNG焊料进行合金化,可以改善焊料的特性。     

Property alterations of Sn-0.6Cu-0.05Ni-Ge lead-free solder by Ag,Bi, In and Sb addition

The Sn-Cu-Ni-Ge solder is a strong challenger to the Sn-Ag-Cu (SAC) solders as a replacement for the Sn-Pb eutectic solder. This research investigated the effects of addition of Ag, Bi, In, and Sb on the physical properties of the Sn-0.6Cu-0.05Ni-Ge (SCNG) lead-free solder and the interfacial reaction with the Cu substrate. The melting behavior, microstructure, tensile strength, and wettability of the SCNG–x (x=Ag, Bi, In, Sb) solders were examined. The findings revealed that the introduction of Ag, Bi, In, and Sb minimally altered the solidus temperature, liquidus temperature, and tensile strength of the solder. However, the cooling behavior and solidified microstructure of the solder were affected by the concentration of the alloying elements. The wettability of the SCNG solder was improved with the doping of the alloying elements except Sb. The thickness of intermetallic layer was increased by the addition of the alloying elements and was related to the cooling behavior of the solder. The morphology of intermetallic layer between the SCNG–x solders and the Cu substrate was different from that of the typical SAC solders. In conclusion, alloying the SCNG solder with Ag, Bi, In or Sb is able to improve particular properties of the solder.