Search Results for heat pumps

Both shape memory and elastocaloric effects are related to the reversible martensitic phase transformation. For the shape memory effect, thermal energy is used to drive the material through the phase transformation and recover its original shape. For the elastocaloric effect, mechanical energy is used to induce phase transformation, and the associated latent heat is used to pump heat for cooling or heating. Heat pumps based on the elastocaloric effect have a low environmental impact and are highly efficient. However, designing a prototype to harvest the full potential of the elastocaloric effect has been challenging. This article summarizes prototyping efforts undertaken by three different research groups.

Successful part brazing relies on proper joint design, part cleanliness, and correct fixturing of part assemblies. Routine furnace maintenance allows repeatable, quality brazing results over time. This article describes aluminum brazing processes and process control considerations.

Residual gas analysis shows that vacuum furnaces with graphite hot zones are more economical than all-metal designs and are capable of producing contamination-free surfaces.

The use of coatings to enhance the performance of components is one of the most powerful tools in materials engineering. This article highlights some examples of how thermal spray technologies are used to enhance surface properties for selected applications and industries.

Temperature measurement, unvented cavities, loose powder, and direct contact of certain metals must be considered during process development for vacuum heat treatment of additively manufactured parts.

Custom equipment designed for the deposition of exotic materials allows advanced coating solutions and ceramic matrix composites to be utilized for applications in automotive, aerospace, defense, energy, and the farthest reaches of space. This article describes custom systems for chemical vapor deposition and advanced materials processing.

Integral quenching (IQ) is a widely adopted heat treatment technique known for its efficient and rapid quenching capabilities. Vertical vacuum IQ furnaces give heat treaters a larger working zone for efficient and rapid quenching. This article describes the elements of a vacuum IQ furnace line and describes its operational workflow and process control.

This case study reviews the considerations in using magnesium thermal spray surfacing to repair a hydraulic pump pad.

Emissivity is a term used to define the ability of a surface to emit and absorb radiation. At any given temperature, the emissivity of a body (or surface) equals its absorptivity. Development work on a vacuum carburizing process revealed the need to better understand the effect of workload surface emissivity and the proper use of dummy thermocouple test blocks. This article reports on the findings from this research effort.

A set of standardized material specifications and test methods now exists to evaluate and maintain quality in shape memory alloys used for medical devices and actuators. This article summarizes the ASTM standards applicable to shape memory technology in medical and actuation applications, and identifies areas requiring further standardization work.

Flow measurement is an increasingly important part of quality control systems in the heat treating industry. This article covers selection basics, sizing, mass flowmeter overview, and frequently asked questions about about flowmeters.

Induction coils are considered the weakest link in an induction hardening system, so advanced designs and precise fabrication are paramount to ensure long life while producing high quality treated parts. This article describes material selection and fabrication techniques for conventional inductors and new breakthrough designs.

Kinetic metallization offers certain advantages over hard chrome and high-velocity oxyfuel thermal spray coatings, especially when elevated process temperatures would degrade the coating or part.

Laser cladding applies thin deposits of hard or corrosion-resistant materials to surfaces susceptible to damage. This article discusses the advantages and drawbacks of laser cladding in comparison to thermal spraying.

Chemical vapor deposition (CVD) of pyrolytic chromium carbide coatings (PCCCs) is proving to be a viable alternative to hard chrome plating used on cylinder piston group components. This article discusses the development and optimization of a CVD process for depositing PCCCs on piston rings and cylinder sleeves. It evaluates the coatings based on friction, wear, and adhesion properties in comparison with coatings produced by other methods.

Shape memory alloy nanowires have been successfully produced from indium-thallium, one of the least-studied binary SMAs. This article provides a brief overview of the process and some of the unique properties of the material. The article is based on the winning entry in the 2012 International Metallographic Contest sponsored by the International Metallographic Society.

Terahertz time-domain spectroscopy is a powerful and nondestructive analytical characterization technique for investigating ceramics, glasses, and composites.

A powder metallurgy and hot isostatic pressing technology offers a new way to manufacture high pressure-retaining components for use in the power-generation industry.

Stringent pressure control and gas species type both play an important role in minimizing the evaporation rate of not only copper, but other elements susceptible to evaporation in vacuum systems. The article describes a study investigating the effect of temperature, pressure, and carrier gas species on the amount of copper evaporation that occurs from copper foil test samples in low pressure carburizing.

This article compares heat treat processes and furnace types that are typically used to harden gears.