Richard C. Evans, 63, a senior chemist on the staff of the Johns Hopkins University's Applied Physics Laboratory in Laurel, died Monday at Montgomery General Hospital in Olney after a heart attack.

He joined the physics lab in 1961 where he worked in the space reliability group. Dr. Evans helped develop an electrical circuit welder in the mid-1960s, which is used for precision welding of rocket parts.

He also did research that helped lead to improved batteries and other packaging materials for electronic equipment, and worked on the Navy Satellite navigation system.

Dr. Evans was a native of Salisbury, Md. and a 1934 graduate of Western High School in Washington. He earned bachelor's and master's degrees at George Washington University and a doctoral degree in chemistry at Johns Hopkins University. He was a member of Phi Beta Kappa.

Before joining the physics lab, he had been a research manager in electrochemistry, thermochemistry, and pyrotechnics with the Olin Corp. in New Haven, Conn. He had worked for Olin from 1952 to 1961.

Dr. Evans was a member of the New York Academy of Sciences, the American Chemical Society, and the American Vacuum Society. He was a resident of Rockville.

Survivors include his wife, the former Patricia Federmann, of Rockville, and three daughters, Emily, of Portland, Ore., Jane, of Rockville, and Anne McCarthy of Cincinnati.

The family suggests that expressions of sympathy be in the form of contributions to the building fund of Washington Cathedral.