Design Layout

Introduction

In the machinery manufacture industry, it is regularly necessary to appear at a metallic constituent with an aluminum casting into a plan by usher in casting process. However, since oxides and impurities on the surface of the usher in are difficult to bathe higher, a metallurgical bonding between the tangible steel usher in and the aluminum casting cannot be ensured. During aluminum usher in casting, the objective of the prevailing task is to realize the bonding of steel usher in with aluminum casting by utilizing the high-power ultrasound. Since the terminal small proportion years high-power ultrasound has been adapted for novel materials fabrication successfully. For case, an ultrasonic reporting is realized in metallic melts during their casting in lead to accept a non-dendritic and a fine-grain solidification microstructure. High-power ultrasound has been adapted to fabricate continuous fiber and particulate fortified steel matrix composites, by transforming the wettability or promoting the chemical reaction between the reinforcement and the steel matrix. In the prevailing task, an ultrasonic usher in cast implement for preparing aluminum or metallic pipe connecting with aluminum alloy was arranged to fabricate a tryout detail of metal/AC4C joint. The consequences of ultrasound task timing and ultrasound goods effected vitality on the bonding strength and microstructure of the steel pipe/AC4C alloy joint were investigated. Combining with these results, the bonding equipment of ultrasonic usher in casting was discussed.

 

Materials and experiment

An aluminum alloy (6063) pipe and a low-carbon metallic pipe were adapted as the usher in materials. The diameter of the couple types of steel pipes was 40mm. The thickness of the aluminum and the metallic pipe was 2mm and 1.5mm, respectively. On the surface of the metallic pipe there was an Al-Si alloy covering (about 18.5µm thick). In the covering of the monolithic pipe, this covering layer was extracted by lathe machining. A cast aluminum alloy AC4C (JIS H5202-1982) was adapted as the casting aluminum. Its nominal composition is (wt%): Si 6.5-7.5, Mg 0.25-0.45, Fe<0.55, Mn<0.35, Cu<0.25, Zn<0.35, Ti<0.2, Al bal. The steel pipe/AC4C joint was fabricated with the implement as shown in Figure 1. First, a steel pipe (65mm long) was inserted into the metallic mold which was preheated to come seal 400°C. Then, the AC4C alloy melt (780°C) was poured into the mold. During solidifying of the AC4C alloy, the ultrasonic vibration was pursued to the pipe by engaging the horn of the ultrasonic generator and a uniting steel plate. Ultrasound task timing can be set in advance. The bonding zone of the pipe with the casting was positioned at the end of the pipe. The goods effected vitality of the ultrasound could be regulated in the range of 0-1000W. The generator had a frequency of 18kHz. Finally, the steel pipe/AC4C joint tryout detail was extracted out of the mold later the AC4C alloy had solidified completely. A compressive shear tryout was adapted to evaluate the bonding strength of the steel pipe/AC4C joint. The glossed phase surface of a joint was discerned and appraised with EPMA (JEOL/JXA-8900RL) to ...