Multi-material assembly and methods of making thereof

A method of making a multi-material assembly comprising:

• providing an elongated frame member having a length, the elongated frame member being formed by hot-stamping a steel blank coated with an AlSi alloy coating, wherein the elongated frame member includes a body, a first leg and a second leg, the first leg including a first end connected to the body and a second end extending outward from the body, wherein the first end and the second end extend along the length of the elongated frame member and the second end defines a portion of a perimeter of the elongated frame member;
• treating an interior surface of the first leg to form a first uncoated portion that has a length that extends along the length of the elongated frame member and is positioned inward of the portion of the perimeter of the elongated frame member defined by the second end, wherein the first uncoated portion is positioned between the first end and the second end of the first leg, wherein the first leg extending from the first end to the first uncoated portion remains coated, and the first leg extending from the first uncoated portion to the second end remains coated;
• providing a reinforcement member including at least a first foot, wherein the reinforcement member comprises a material that is dissimilar from the elongated frame member;
• applying an adhesive to the first foot of the reinforcement member or the first uncoated portion of the first leg;
• positioning the reinforcement member between the first leg and the second leg with the first foot positioned opposite the first uncoated portion with the adhesive positioned therebetween;
• and
• curing the adhesive to secure the first foot to the first uncoated portion.