Deformation and strengthening of sintered ferrous material

Proceedings of the Institution of Mechanical Engineers, Part B:

2014

Experimental investigation has been carried out to evaluate the effect of titanium carbide (TiC), molybdenum carbide (Mo2C), iron carbide (Fe3C) and tungsten carbide (WC) addition on the composite aluminium preforms. The hot upsetting of the composite aluminium preforms with various carbide contents, namely, Al-4% TiC, Al-4% WC, Al-4% Fe3C and Al-4% Mo2C, and different aspect ratios, namely, 0.4 and 0.6, was carried out and the workability behaviour of the same was determined. The influence of carbide addition in the aluminium composite and initial preform geometry on the relative density ( R), stress ratio parameters, [Formula: see text], [Formula: see text] and [Formula: see text], and formability stress index was studied.

Section: Theoretical Analysismentioning

confidence: 99%

Section: Theoretical Analysismentioning

confidence: 99%

Workability studies of sintered aluminium composites during hot deformation

Proceedings of the Institution of Mechanical Engineers, Part B:

2014

“…The effective or equivalent stress for powder metallurgy materials can be determined by using the appropriate yield criterion which should take the pore effect into account. A typical theorem is that the plastic deformation occurs when the elasticity strain energy reaches a critical value [30][31][32].…”

Section: Theoretical Analysismentioning

confidence: 99%

Workability Behaviour of Powder Metallurgy Aluminium Composites

Journal of Powder Technology

2014

An efficient way to find the workability limit for powder metallurgy parts has been suggested. Compacts of Al-4%TiC, Al-4%WC, Al-4%Fe3C, and Al-4%Mo2C were produced to the relative density of 0.82 and 0.86 with three different geometries through primary operations of powder metallurgy routes. Each sintered compact was hot deformed to various strain levels till a visible crack appeared at the free surface. Oyane’s fracture principle was used to develop a theory to study powder metallurgy compacts. A least square technique was used to determine the constants in fracture criteria and these equations were finally used to find workability limit. It is found that the projected technique was well in agreement with the experimental values.

“…The plastic deformation behaviour of porous metals is influenced by the internal pores, and the analysis of porous metals requires an appropriate yield criterion which should take the pore effect into account. Many researchers over the years have analysed several different yield criteria for sintered powder materials which are based on experimental and theoretical analysis [20][21][22][23]. A typical theorem is that the plastic deformation occurs when the elasticity strain energy reaches a critical value.…”

Section: Theoretical Analysismentioning

confidence: 99%

Influence of carbon content on densification behaviour in forming of sintered plain carbon steel preforms

Proceedings of the Institution of Mechanical Engineers, Part B:

2011

Complete experimental investigation on the deformation and densification behaviour of sintered plain carbon steel cylindrical preforms with carbon contents of 0, 0.35, 0.75 and 1.1 per cent, under cold upsetting, have been studied in order to understand the influence of various forming parameters such as true axial strain, flow stress, Poisson's ratio, forming limits and formability stress index on the densification process. The above-mentioned powder metallurgy sintered preforms with constant initial theoretical density of 84 per cent and aspect ratio of 0.4 were prepared using a suitable die-set assembly on a 1 MN capacity hydraulic press and sintered for 90 min at 1200 °C. Each sintered preform was cold upset under two different frictional constraints, namely, nil/no and graphite lubricant conditions. Densification–true strain and fracture strain–carbon content relationship was established and presented in this work. Further, attained density is considered to establish flow stress and formability stress index behaviour. The present work provides a guideline for producing P/M components free from open surface pore.