The Effect of Process Parameters in Interdendritic-Melt Solidification Control Technique on the Microstructure and Properties of a Ni-Base Superalloy

A novel technique called interdendritic-melt solidified control (IMSC) was developed to manufacture equiaxed superalloy in the efforts of reducing porosity. The effect of process parameter, such as withdrawal rate, of the IMSC on the porosities and mechanical properties of IN792 alloy was investigated, compared with conventional investment casting (CC) technique. The IMSC and CC samples were characterized by optical metallography and scanning electron microscopy. In addition, the minor phases, such as MC carbides and trace amount of η phase, were identified by synchrotron X-ray diffraction. The results indicate that proper withdrawal rate for IMSC can produce castings with much reduced porosity and higher stress rupture properties at elevated temperature compared to conventional investment casting. However, fast withdrawal rate will produce much severe porosity and lower mechanical property.

Solidification Control by Thermal Analysis of La/Ba Inoculated Grey Cast Iron

Thermal analysis is worldwide used in foundry for control of structure and properties of cast irons. In this paper is presented the experimental study realized to control the inoculation effect by thermal analysis method of inoculated grey cast irons. For this purpose was conducted an in ladle inoculation process with 0.5wt. % inoculant from LaCaAlFeSi and BaCaAlFeSi alloy systems. The main goals of this experimental research work are: to determine the particular characteristics of the registered cooling curves, to notice the solidification parameters that present sensibility as against inoculant addition in treated cast iron and eventually to improve thermal analysis technique of cast irons.

Research Status and Development Trend of Horizontal Welding Technology

The difficulties of horizontal welding technology are stated in this paper. On the basis of analyzing the defects occurred during horizontal welding technology as well as several corresponding methods are adopted nowadays. Control measures for horizontal welding technology high efficiency can be summed up to two types: weld pool quick solidification control measure and weld pool stable shape measure. The development history of their research and application is reviewed. And the mechanism of producing weld defects is deeply analyzed. The prospects and development of horizontal welding technology are elaborated.

Development and Prospect of Al Scraps Reproduction Technology in China

Al scraps reproduction was the need of sustainable development. The main factors which influenced the quality of Al alloy recycling products was contaminating elements and non-metallic inclusions. Thus the critical technique in promoting the Al scraps reproduction process was how to relieve the harmful effect of non-metallic inclusions and effectively control the types and number of impurity elements. The research for Al scraps reproduction should be developed as a individual system, main contents includes effective separation of varies metallic materials, remove of contaminating elements, solidification control, etc. and furthermore study the technology of high ratio of Al recovery and improve the process of saving energy, lower consumption and reduce pollutants.