Novel lead-free bronze alloys

Lead has long been used in metal parts due to its ability to make alloys easy to machine and process, and also to provide lubrication for sliding components such as bushings and bearings. However, when lead-containing alloys are used in sliding components, their wear particles contribute to environmental lead. We are creating lead-free bronze alloys for multiple industrial applications, including bushings and bearings. 

Current alternatives for leaded alloys have manufacturing, material property and cost limitations. However, a family of copper-based alloys (including a number of other elements) that was developed by previous HMC students and our group’s Australian* collaborators is an excellent base for new alloy applications. Last year, HMC students successfully integrated graphite into novel bronze alloys, which is challenging because carbon is insoluble in copper! In the coming year we will use the alloy base to continue to develop alloys that have desired properties, favorable economics for industrial adoption, and no lead.

This project is multidisciplinary hands-on on work. Students learn and use relevant thermodynamic principles to select alloy compositions and heat treatments; create alloy samples from pure element constituents using an arc melter or induction furnace; analyze sample mechanical properties such as hardness (indenter), strength and ductility (MTS machine), and other deformation behavior (rolling mill); analyze sample microstructure (map compositions and phases using energy dispersive spectroscopy (EDS) in a scanning electron microscope); and then refine compositions. No student in the group does every part of this, each chooses which are most interesting. 

*Our group travels to the University of New South Wales in Sydney, Australia for summer research! Background learning work in spring is important so students can be prepared for this experience. See keets.org for more about our collaboration on this project and others. In addition to the standard research stipend, travel and living expenses are covered.

New group members will be invited to join current members and Australian collaborators at the TMS conference in March 2026.

Essay Prompt - What is your motivation to conduct research in general and in this project in particular? Describe your relevant background and/or desire to learn specified skills. 

Also please:

• Explain how many units you would like to sign up for (between one and three) in spring 2026 (and fall 2026, as students typically continue on projects) and how adding these additional units would fit into your academic plan. Note that each unit requires approximately three hours of research work per week plus meetings.

• Provide names of two HMC professors who could provide references on your work style (please say the context in which they know you. Professors from project or lab classes (or previous research) might be especially good choices.)

• Submit on URO or email to bassman@g.hmc.edu your resume or, if you don’t have one, a list of activities that you are involved in at HMC (extracurricular activities, projects, or anything outside of academics). 

Very soon after the application window closes, applicants will be selected for an interview with Prof Bassman and a current student.