Cryogenically assisted manufacturing processes are emerging as environmentally-benign, toxic-free, hazardless operations, producing functionally superior products. This paper presents an overview of major cryogenic manufacturing processes, summarizing the state-of-the-art and significant developments during the last few decades. It begins with a summary of historic perspectives, including definitions, scope, and proceeds to analysis of process mechanics and material performance covering tribological and thermo-mechanical interactions, followed by surface integrity, product quality and performance in cryogenic manufacturing. Process analysis and applications includes machining, forming and grinding. Economic, safety and health issues are then discussed. Finally, progress in developing predictive performance models and future outlook are presented.

Cryogenic manufacturing processes

Excellent thermal conductivity and lower density make Al–Si alloys a suitable alternative for cast iron in the fabrication of engine components. The increase in the maximum operation temperature and pressure of engines necessitates improving the thermomechanical fatigue performance of Al–Si alloys. This paper has two major parts focussing on the use of Al–Si based alloys in cylinder heads and engine blocks.In the first part, the structural stress–strain and material property requirements of cylinder heads are discussed. In addition, the physical and mechanical properties of different competing materials used in the manufacture of engine components are reviewed. The physical metallurgy, solidification sequence and thermal conductivity of Al–Si based alloys are reviewed. Also discussed is the effect of microstructural features on thermomechanical fatigue lifetime. This part also includes an overview of the strengthening mechanisms of cast Al–Si alloys, by dispersed phases and heat treatment.Demands ...

Application of cast Al–Si alloys in internal combustion engine components

This article is a state-of-the-art review of the use of cryogenic cooling using liquefied gases in machining. The review is classified into two major categories, namely cryogenic processing and cryogenic machining. In cryogenic processing also known as cryo-processing, the cutting tool material is subjected to cryogenic temperatures as a part of its heat treatment process. The majority of the reported studies identify that cryo-processing can considerably increase cutting tool life especially for high speed steel tools. It also identified that, in cryogenic machining, a cryogen is used as a cooling substance during cutting operations. The cryogen can be used to freeze the workpiece material and/or cutting tool. This article concludes that cryogenic cooling has demonstrated significant improvements in machinability by changing the material properties of the cutting tool and/or workpiece material at the cutting zone, altering the coefficient of friction and reducing the cutting temperature.

/pdf/state-of-the-art-cryogenic-machining-and-processing-48qg03vwr8.pdf

State-of-the-art cryogenic machining and processing

Cryogenic treatment (CT) of materials has shown significant improvement in their properties. Various advantages like increase in wear resistance, reduced residual stresses, increase in hardness, fa...

Cryogenic Treatment of Tool Materials: A Review

/pdf/advanced-modeling-and-optimization-of-manufacturing-13zl35m5o1.pdf

Advanced Modeling and Optimization of Manufacturing Processes

Effect of deep cryogenic treatment on wear resistance and tool life of M2 HSS drill

In this investigation, the effect of microstructural constituents on thermal fatigue resistance of A319 aluminum casting alloy was studied. For this purpose, both thermo-mechanical fatigue and thermal-shock fatigue experiments were performed in thermal cycling range between 40 and 250 °C. Following the results, samples with finer SDAS, lower porosity volume fraction and lower brittle intermetallic contents, as well as higher Si modification showed better thermal fatigue resistance. Moreover, T6 and T7 heat treatments appeared to be highly beneficial for thermal fatigue performance. According to the fractography analysis, porosities and coarse intermetallic phases were determined as the most prime locations for crack propagation.

E. Nejati

Papers

Effect of deep cryogenic treatment on wear resistance and tool life of M2 HSS drill

Effect of microstructural constituents on the thermal fatigue life of A319 aluminum alloy