In this article, interface characteristics of aluminum and CAST IRON bimetal has been investigated. To reach an acceptable composite products, from two materials, interface characteristics needs to be investigated. Aluminum melt was poured, at 700 and 750oC, around cylindrical CAST IRON bars having melt/solid volume ratios of 3, 5 and 8, respectively. Optical and SEM microscopic observations showed that a reaction layer may form at the interface. This layer is composed of Fe2Al5 intermetallic which forms initially at the rough surface of the insert after making contact with molten metal. Microstructural analysis showed the increasing of temperature and the Vm/Vs ratio leads to formation of a thicker and more uniform intermetallic layer. Microhardness of the Fe2Al5 was 824 HV and the thickness of interaction layer varied from 5μm, for the sample produced at 700oC and 3 Vm/Vs, up to 20μm for the sample poured at 750oC and 8 Vm/Vs. A mechanism is suggested for nucleation and growth of this intermetallic layer and also graphite engulfment of gray CAST IRON, by aluminum melt, at the interface of two metals.

From the standpoint of processing, hard chromium layer plate may be applied to steels, CAST IRON, aluminum and nickel base alloys. CAST IRON can be plated provided that the surface is capable of conducting the required current and is reasonably free of voids, pits, gross silicate inclusions, and massive segregation. There are many difficulties arising from graphite phase and deposition of hydrogen on the surface of gray CAST IRON (G.C.J). To obtain desired hard chromium coating with acceptable adhesion, special pretreatments should be used. In this paper the surfaces of G.C.I. were prepared in sulphuric acid, chromic acid + S04-- by anodic etching phosphoric acid + sulphuric acid solution by electro polishing and sulphuric acid + fluoridric solution by dipping in the different conditions. The best results for removal of graphite from the surface of specimens are obtained after anodic etching in 60% H2S04 solution.

An improved chemical composition for the production of the black oxide coatings, termed blackening on CAST IRON, and its particular relation to optimum conditions for CAST IRON blackening in the presence of chromium and silicon is studied. Black oxide coating process at different dwell times, temperatures of chemical bath, chemical compositions of coating bath and different preparating conditions of substrates were investigated and their effects on coating quality were discussed. Comprehensive researches illustrate that at higher chemical bath temperatures and immersion time of parts, the coating thickness increases up to one micrometer, but protecting effects and adhesion of coating decreases. Chemical bath temperature between 130oC to 140oC and contact times of 20 minutes was observed as optimum. In addition, the effects of the compositions of the bath on the quality of black colored layer are discussed. It is shown that when potassium salts were used in blackening bath the quality of coating improved and optimum compositions of chemical blackening bath is given. The optimum bath compositions were obtained as follows: 70 weight percent of potassium hydroxide, 10 weight percent of potassium nitrite and 20 weight percent of potassium nitrate. Furthermore; it is shown that acid pickling with one molar sulphuric acid for five minutes before blackening step result in higher adhesion and coating quality.

In this paper, the metal matrix composites containing 22 wt % Cr, 2.5 wt % C and 2 to 16 volume percent TiC were processed by solidifying Fe-Cr-Ti-C in which precipitation of titanium carbide and chromium carbide occurred. The microstructure and abrasion resistance of in-situ synthesized composites were compared with the unreinforced high chromium white CAST IRON (HCWCI) containing 22 w. t. % Cr and 2.5 w. t. % C. SEM, OM as well as abrasion machine test methods which were used for microstructure and wear evaluation of the matrix and reinforcement. As a result, an increase in Ti content, increased the hard TiC volume percent besides the coarse (Fe,Cr)7C3 in the ferrous matrix. The increase of the TiC content led to an increase in wear resistance, without any considerable increase in macro hardness.

In this research, the machinability of IRON-recycled grey CAST IRON powder metallurgy parts is investigated. For this purpose, grey CAST IRON swarfs were transformed to powders by target jet milling method and were then used to prepare powder metallurgy parts in combination with commercial IRON powder. Green compacts were prepared with the variables of CAST IRON powder percentage and compaction pressure. Design of experiments was conducted by response surface method for sintered parts with the variables of CAST IRON powder percentage, compaction pressure, sintering temperature and sintering time each in five levels. Regression analysis and analysis of variance were used to investigate the effect of input parameters, develop the mathematical models and evaluate the validity of the models. In the green section, machinability was qualitatively investigated in drilling. For sintered parts, machinability was evaluated by measuring the thrust and torque forces and the obtained surface finish in drilling. The obtained results certificated the accuracy of the extracted regression equations for predicting the machining properties of the parts. Also, the results demonstrated that the addition of jet milled grey CAST IRON improves the machinability of IRON-based powder metallurgy parts.

In this investigation a new procedure has been developed for producing of CAST IRON parts. The CAST IRON parts were produced as two layers during of solidification. They had two zones, outer zone which was Grey IRON and inner zone which was Ductile IRON. At first, a complex CAST part with a blind riser was designed. Second, some inoculants were placed into the blind riser on a wire screen for inoculation of melt. Finally, the micro structure from the outer skin toward the inner zone of the part was investigated by metallographic testing. Results showed that graphite’s in outer layers were from type of flack graphite, and the central zones were spherical graphite. In fact, at the first step of solidification, outer skin is solidified as Grey IRON. Then due to contact melt and inoculants material concurrent with cavity shrinkage as well as back pressure into the riser, a flow of inoculated melt move from the riser toward mold cavity. This phenomenon lead to formation of spherical graphite’s at the central zones. This procedure is very economic fore CASTing industries, because in this technique the blind riser has the role of a reaction cavity, instead of melt compensation.

The aim of this work is determining the effect of the addition of a reinforced-phase into steel and CAST IRON matrix ferrotic composites. The In-situ method was performed to synthesize the composites containing titanium and graphite (weight ratio 4:1). The microstructures were examined under scanning electron and optical microscopes. The hardness and wear test were used to determine the properties of the specimens. Results have shown that in the as-CAST and heat treated CAST IRON matrix composites, wear resistance increases with volume percent of TiC until 6. In all steel matrix composites, wear resistance increases with the volume fraction of TiC. In steel and CAST IRON matrix composites containing less than 6 volume percent of TiC, quenching heat treatment causes an increase in wear resistance.