Bonding metal members with multiple laser beams

A method of using multiple laser beams to bond metal members, comprising:

• generating a first pulsed laser beam;
• generating a second pulsed laser beam with a longer wavelength than the first laser beam;
• contacting first and second metal members wherein at an ambient temperature the first member has high absorption of energy from the first laser beam but low absorption of energy from the second laser beam, and wherein high absorption is greater than or equal to 10 percent of the energy in the laser beam where the laser beam impinges upon the first member and low absorption is less than 10 percent of the energy in the laser beam where the laser beam impinges upon the first member;
• directing the first laser beam at the first member at the ambient temperature wherein the first member absorbs energy from the first laser beam, the temperature of the first member increases and the reflectivity of the first member decreases so that the first member has high absorption of energy from the second laser beam;
• directing the second laser beam at the first member while the first member has high absorption of energy from the second laser beam so that the first member absorbs energy from the second laser beam, the temperature of the first member further increases and both of the members melt;
• and
• discontinuing to direct the laser beams at the first member, thereby cooling the members and forming a solid bond between the members.

An apparatus with multiple laser beams for bonding metal members, which comprises:

• means for generating a first laser beam;
• means for generating a second laser beam with a longer wavelength than the first laser beam;
• a first metal member wherein at an ambient temperature the first member has high absorption of energy from the first laser beam but low absorption of energy from the second laser beam;
• a second metal member;
• means for holding the first and second members in contact with one another;
• means for directing the first laser beam at the first member at the ambient temperature wherein the first member absorbs energy from the first laser beam, the temperature of the first member increases and the reflectivity of the first member decreases so that the first member has high absorption of energy from the second laser beam without roughening the surface of the first member;
• means for directing the second laser beam at the first member while the first member has high absorption of energy from the second laser beam so that the first member absorbs energy from the second laser beam, the temperature of the first member further increases and a member melts;
• and
• means for discontinuing to direct the laser beams at the first member so that the molten member cools and a solid bond forms between the members.

An apparatus with multiple laser beams for bonding metal members, which comprises:

• means for generating a first pulsed laser beam;
• means for generating a second pulsed laser beam with a longer wavelength than the first laser beam;
• a first metal member wherein at an ambient temperature the first member has high absorption of energy from the first laser beam but low absorption of energy from the second laser beam, and wherein high absorption is greater than or equal to 10 percent of the energy in the laser beam where the laser beam impinges upon the first member and low absorption is less than 10 percent of the energy in the laser beam where the laser beam impinges upon the first member;
• a second metal member;
• means for holding the first and second members in contact with one another;
• means for directing the first laser beam at the first member at the ambient temperature wherein the first member absorbs energy from the first laser beam, the temperature of the first member increase and the reflectivity of the first member decreases so that the first member has high absorption of energy from the second laser beam without roughening the surface of the first member;
• means for directing the second laser beam at the first member while the first member has high absorption of energy from the second laser beam due to said temperature increase in the first member caused by energy from the first laser beam so that the first member absorbs energy from the second laser beam, the temperature of the first member further increases and both members melt;
• and
• means for discontinuing to direct the laser beams at the first member so that the members cool and a solid bond forms between the members.